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I 


JOHNA.SEAVERNS 


Webster  FamiK/  ?J''       if  V^'^'^nnary  Medicine 

Cumming? "  ch'  „6n     .  Medicine  at 

Tufts  Univ^.  :;ii! 

200W8Stboro"; 

North  Grafton,  MA  01536 


^6e  Eucal  ^tizixtt  ^nk^s 

Edited  by  L.  H.  Bailey 


THE    FEEDIXCI   OF   ANIMALS 


%fit  Eutal  Science  ^ttit^ 

The  Soil. 

The  Spraying  op  Plants. 

Milk  and  its  Products. 

The  Fertility  of  the  Land. 

The  Principles  of  Fkuit-Growing. 

Bcsh-Fruits. 

Fertilizers. 

The  Principles  of  Agriculture. 

Irrigation  and  Drainage. 

The  Farmstead. 

Rural  Wealth  and  Welfare. 

The  Principles  of  Vecjetable-Gardening. 

Farm  Poultry. 

The  Feeding  of  Animals. 


THE 

FEEDIA^G  OF  ANIMALS 


BY 

WHITMAN    HOWARD    JORDAN 

Director  of  the  New  York   Agricultural   Experiment   Station 


THE    MACMILLAN    COMPANY 

LONDON:    MACMILLAN  &  CO.,  Ltd. 

1901 

All  rights  reserved 


:i^Y^  \  1  o 


:> 


s:2 


Copyright,  1901 
By   the    MACMILLAN    COMPANY 


0Bount   ©Icajaant   IIDrmterp 

J    Horace  McFari.and  CowrANY 
Harrisburo  •  Pennsylvania 


PREFACE 

This  volume  is  the  result  of  an  effort  to  present 
the  main  facts  and  principles  fundamental  to  the 
art  of  feeding  animals,  as  they  are  now  understood. 
It  is  not  a  statement  of  rules  or  of  the  details  of 
practice,  for  even  if  the  author  regarded  himself  as 
competent  to  discuss  these  he  would  hold  it  to  be 
unwise  to  attempt  to  discriminate  in  practical  matters 
so  varied  and  so  complex. 

Neither  has  an  effort  been  made  to  harmonize  the 
whole  mass  of  experimental  data  relating  to  animal 
nutrition.  Many  of  these  data  are  of  no  value,  many 
are  verj'  incomplete,  and  many  are  apparently  con- 
flicting, so  that  more  useful  lessons  can  often  be 
drawn  from  single  events  in  the  field  of  experiment 
and  investigation  than  from  the  frequently  doubtful 
testimony  of  summaries. 

The  author  expresses  the  hope  that  what  he  has 
written  will  not  be  regarded  as  having  for  its  ulti- 
mate object  the  mere  exposition  of  feeding  formulas. 
It  is  to  be  feared  that  the  German  standard  rations 
are  unfortunately  accepteil   l)y  manj-   as   nutrition  pre- 

rv) 


VI  Preface 

scriptions  "to  be  given  according  to  directions."  It 
is  time  to  break  away,  if  we  have  not  already  done 
so,  from  an  nndiscriminating  adherence  to  mathe- 
matical doses  of  nutrients,  the  accuracy  of  which  is 
supposed  by  some  to  outweigh  all  other  consider- 
ations and  to  determine  success  in  feeding.  The 
study  of  animal  nutrition  may  not  wisely  center 
around  feeding  standards,  as  seems  to  have  been  the 
tendency  of  late  years.  While  these  formulas  are 
certainly  an  aid  in  selecting  adequate  and  uniform 
rations,  they  are  nevertheless  merely  an  imperfect 
expression  of  relations  not  fully  understood  that  have 
a  greatly  variable  application  in  practice,  an  appli- 
cation judiciously  made  only  through  the  exercise  of 
a  judgment  enlightened  b}'  familiarity  with  funda- 
mental facts  and  principles.  Rational  cattle  feeding 
is  not  to  be  attained  through  a  blind  acceptance  of 
existing  standard  rations  but  by  means  of  a  broad 
understanding  of  the  scientific  and  practical  knowl- 
edge in  which  these  standards  had  their  rise. 

Much  of  the  matter  introduced  in  this  connection 
bears  no  immediate  relation  to  the  practical  opera- 
tions of  feeding.  No  apology  is  made  for  this  de- 
parture from  the  business  aspects  of  the  subject.  A 
study  of  the  practical  relations  of  science  should  not 
only  promote.- our  material  w^ell-being  but  should  also 
lend  itself  to  intellectual  stimulus  and  culture. 


Preface  vii 

The  chapter  on  The  FeediDg  of  Poultry  was  writ- 
ten by  Mr.  William  P.  Wheeler,  who  also  executed 
the  several  drawings  which  appear  as  illustrations. 
The  author  is  under  great  obligations  to  his  associ- 
ates, Dr.  L.  L.  Van  Slyke  and  Mr.  Frank  H.  Hall, 
for  reading  the   proof  sheets. 

W.  H.  JORDAN. 

New  York   State  Experiment  Station, 
Geneva,  N.  Y.,  June   1,   1901. 


1 


1 


CONTENTS 

PART    I 

THE   PRINCIPLES    OF  FEEDING 
CHAPTER    I 

PAGES 

Introduction:   Man's  Relation  to  Animal  Life 16 

The  conditions  and  problems  involved  in  feeding  animals  .    .    3 

CHAPTER   n 

The  Relations  of  Plant  and  Animal  Life 7-10 

CHAPTER    III 

The  Chemical  Elements  of  Nutrition 11-24 

The  elements  and  their   sources:     Carbon,  Oxygen,  Hy- 
drogen,   Nitrogen,    Sulfur,    Phosphorus,    Chlorine, 

Potassium,  Sodium,  Calcium,  Iron 12 

Proportions  of  elements  in  plants  and  animals 21 

In  plants 21 

In  animals 22 

CHAPTER    IV 

The  Compounds  of  Animal  Nutrition 25-50 

Classes  of  matter 26 

(ix) 


Confenfs 

PAGES 

The  classes  of  compounds 28 

WaMr 30 

Water  in  living  plants 33 

Water  in  feeding  stuffs 3G 

Water  in  the  animal 38 

Ash 41 

The  mineral  compounds  of  i)hiiits 43 

Variations  due  to  species      43 

The  distribution  of  mineral  comi)Ounds  in  the  dif- 
ferent parts  of  the  j)];uit 45 

Influence   of    manufacturing   processes   on   the    ash 

constituents      47 

The  mineral  compounds  of  atiimnl  bodies      ....  48 
The   distribution    of    inorganic    compounds    in    the 

animal  body 49 


CHAPTER    V 

The  Compounds  of  Animal  Nutrition  (continued)    .    .    .    51-70 

The  nitrogen  compounds 51 

Protein 52 

The  proteids 55 

The  albuminoids 57 

The  albumins 58 

The  globulins 59 

The  modified  albuminoids G2 

Coagulating  ferments      63 

Heat 64 

Action  of  acids  and  alkalies 65 

Ferments  of  digestion 65 

Combinations C- 

The  gelatinoids 6o. 

Keratin  and  similar  substances 69 

Protein:    The  non-proteids 69 

Amides 69 

Extractives 70 


Contents  xi 


CHAPTER    VI 

PAGES 

The  Compounds  of  Animal  Nutrition  (concluded)     .    .    .    71-92 

The  nitrogen -free  compounds 71 

Crude  fiber 72 

Nitrogen-free  extract 74 

The  starches 75 

The  vegetable  gums , 78 

The  pectin  bodies 80 

The  sugars 80 

The  acids 83 

Animal   carbohydrates 84 

Chemical  relations  and  characteristics  of  the  carbohy- 
drates       85 

Fats  or  oils      . 88 

CHAPTER  VII 
The  Composition  op  the  Bodies  of  Farm  Animals  .    .    .    93-97 

CHAPTER  VIII 

The  Digestion  of  Food 98-125 

Ferments 99 

The  mouth 104 

The  stomach      108 

The  intestines 114 

Absorption  of  the  food 119 

Feces 121 

Relation  of  the  different  feeding  stuff   compounds  to  the 

digestive  processes 121 

CHAPTER  IX 

Conditions  Influencing  Digestion 126-141 

Palatableness 126 

Influence  of  quantity  of  ration 127 


xii  Contents 

PAGES 

Effect  of  drying  fodders 128 

Influence  of   the    conditions   and    methods    of    preserving 

fodders 129 

Influence  of  the  stage  of  growth  of  the  plant 130 

Influence  of  methods  of  preparation  of  food 131 

Influence  of  grinding 133 

Effect  of  common  salt • 133 

Influence  of  frequency  of  feeding  and  watering  animals  .  134 

Influence  of  certain  other  conditions 134 

Influence  of  the  combination  of  food  nutrients 135 

Conditions    pertaining    to    the    animal  :     species,    breed, 

age  and  individuality 137 

Determination  of  digestibility 139 


CHAPTER  X 

The  Distribution  and  Use  of  the  Digested  Food     .    .  142-150 

The  blood 142 

The  heart 144 

The  lungs 146 

The  use  of  food 147 

Elimination  of  wastes 148 

The  liver 150 


CHAPTER  XI 

The  Functions  op  the  Nutrients 151-169 

Functions  of  the  mineral  compounds  of  the  food    ....  152 

Functions  of  protein 153 

Functions  of  carbohydrates 155 

Functions  of  the  fats  and  oils 157 

Food  as  a  source  of  energy 157 

Available  energy 163 

Net  energy 164 

Encrg)'  relations  of  the  several  nutrients 166 

Heat  relations 167 


Contents  xiii 

CHAPTER  XII 

PAGES 

Physiological  Values  of  the  Nutrients 170-181 

Relative   energy  and  production  vahits  of  the   nutrients, 

singly  and  as  classes 171 

Relative  energy  values 171 

Relative  production  values  of  the  different  nutrients  .     175 
Relative  importance  of  the  protein  compounds  ....    178 

CHAPTER  XIII 
Laws  of  Nutrition 182-185 

CHAPTER  XIV 

Sources  of  Knowledge 186-202 

Conclusions  of  practice 187 

Practical  feeding  experiments •    •  1^8 

Chemical  and  physiological  studies  .    .    .    / 191 

More  accurate  methods  of  investigation 192 

Relation  of  food  to  production 194 

The  respiration  apparatus 196 

Determination  of  energy  values 198 

Calculation  of  energy  value  of  a  ration 198 

Energy  value  of  digested  nutrients 199 

Measurement  of  food  combustion 200 

Respiration  calorimeter 201 


PART    IT 

THE   PRACTICE    OF  FEEDING 

CHAPTER    XV 

Cattle  Foods  —  Natural  Products 203-226 

Forage  crops 204 

Green  vs.  dried  fodders       205 

The  harvesting  of  forage  crops 207 


xiv  Contents 


PAGES 

Silage :   .    .    .  212 

Nature  of  changes  in  silo 213 

Extent  of  loss  in  the  silo 215 

Ensiling  vs.  field-curing 217 

Crops  for  ensilage 218 

Construction  of  silos 219 

Filling  the  silo 220 

The  straws 223 

Roots  and  tubers      224 

Grains  and  seeds 225 


CHAPTER    XVI 

Cattle  Foods — Commercial!  Feeding  Stuffs 227-257 

Classes  of  commercial  by-product  feeding  stuffs 228 

Wheat  offals 228 

Residues  from  breakfast  foods 232 

Brewers'  by-products 236 

Residues  from  starch  and  glucose  manufacture    ....  236 

Residues  from  the  manufacture  of  beet-sugar    ....  240 

The  oil  meals  in  general 241 

Cottonseed  meal 242 

Linseed  meal 245 

Chemical  distinctions  in  cattle  foods 248 

Coarse  foods  vs.  grains  and  grain  products 249 

Classification  according  to  the  proportions  of  nutrients  .  249 

Foods  of  animal  origin 252 

Milk    .    .* 252 

Dairj"  by-products 254 

Slaughter-house  and  other  animal  refuses 256 


CHAPTER  XVII 

The  Production  of  Cattle  Foods 258-267 

Soiling  crops 263 


1 


Contents  xv 

CHAPTER   XVIII 

PAGES 

The  Valuation  of  Feeding  Stuffs 268-279 

Commercial  values 269 

Physiological  values 272 

Selection  of  feeding  stuffs 273 

Other  standards  of  valuation 277 

CHAPTER   XIX 

The  Selection  and  Compounding  of  Rations 280-294 

CHAPTER   XX 

Maintenance  Rations 295-303 

Maintenance  food  for  bovines 297 

Maintenance  food  for  horses 300 

CHAPTER  XXI 

Milk  Production 304-323 

Milk  secretion 306 

Sources  of  milk  solids 307 

The  rate  of  formation  of  milk  solids 308 

The  amount  and  character  of  the  ration  for  milk  production  309 

The  sources  of  protein  for  milk  production 313 

The  relation  of  food  to  the  composition  and  quality  of  milk  316 

Effect  of  food  upon  the  composition  of  milk 316 

Effect  of  food  upon  the  flavors  of  milk  and  its  products  .  321 

CHAPTER   XXII 

Feeding  Growing  Animals 324-338 

The  feeding  of  calves 328 

The  feeding  of  lambs 331 

Feeding  colts 333 

Feeding  the  dam 334 

Feeding  the  colt 335 


xvi  Contents 

CHAPTER   XXIII 

PAGES 

Feeding  Animals  for  the  Production  of  Meat  ....  339-366 

The  nature  and  extent  of  the  growth  in  beef  production  .  340 

The  food  needs  of  the  fattening  steer  .    .        341 

The  selection  of  a  fattening  ration 347 

Mutton  production 349 

The  nature  and  extent  of  the  growth  in  fattening  sheep  .  350 

Food  needs  of  fattening  sheep 351 

The  selection  of  a  ration  for  sheep 355 

Pork  production 357 

Character  of  the  growth  in  pork  production 358 

Food  requirements  for  pork  production 360 

Feeding  the  dam 360 

Feeding  pigs  for  the  market 361 

CHAPTER  XXIV 

Feeding  Working  Animals 367-378 

The  horse  a  machine      367 

The  work  performed  by  a  horse 368 

The  food  requirements  of  a  working  horse 371 

Source  of  the  ration  for  working  horses 374 

CHAPTER   XXV 

The  Feeding  of  Poultry  — By  William  P.  Wheeler   .    .  379-399 

Kinds  of  foods 379 

Incidental  effects  of  the  food 382 

Digestive  apparatus 383 

Constituents  of  the  body 387 

Necessity  for  considering  the  water 389 

The  organic  and  mineral  nutrients  in  food 389 

The  study  of  rations  and  deduction  of  standards    ....  392 

Maintenance  rations 393 

Rations  for  laying  hens 393 

Rations  for  young  birds 394 


Contents  xvii 


CHAPTER    XXVI 

PAGES 

The  Relation  op  Food  to  Production 400-407 


CHAPTER   XXVn 

General  Management 408-418 

Selection  of  animals 409 

Selection  of  cows 409 

The  selection  of  animals  for  meat  production    ....  411 

Manipulation  of  the  ration 413 

Quantity  of  the  ration 414 

Environment  and  treatment  of  animals 415 


APPENDIX 

Composition  and  Digestion  Tables 419-443 

1.  Average  composition  of  American  feeding  stuffs  .    .  419-427 

2.  Average  coefficients  of  digestion 427-435 

3.  Feeding  standards 435-438 

4.  Fertilizing  constituents,  American  feeding  stuffs   .    439-443 


INDEX 445-450 


THE  FEEDmG  OF  ANIMALS 


PART  I— TEE  FBINCIPLES  OF  FEEDING 
CHAPTER  I 

INTRODUCTION:   MAN'S  RELATION  TO  ANIMAL  LIFE 

There  was  a  time  somewhere  iu  the  dim  past  when 
the  beast  of  the  fiekl  knew  no  master.  The  only  obe- 
dience which  he  rendered  to  a  snperior  power  was  an 
nnconscions  submission  to  Nature's  stern  forces.  He 
wandered  forth  at  will  to  find  in  the  untilled  pastures 
such  food  as  the  wild  herbage  afforded,  and,  unre- 
strained, he  sought  a  place  of  rest  in  the  tangled 
thicket.  He  knew  no  refuge  from  the  winter's  cold 
and  storm  but  some  sheltered  nook  or  forest  recess  to 
which  his  brute  intelligence  guided  him,  and  he  was 
his  own  defense  against  the  dangers  which  beset  him. 

Man  had  not  come  to  be  a  controlling  factor  in  the 
development  of  the  various  forms  of  animal  life.  If 
the  brute  knew  him  at  all,  it  was  as  the  huntsman,  as 
an  enemy,  but  not  as  a  superior  to  whom  must  be  paid 
a  tribute  of  service  or  of  food  and  clothing.  The  wild 
ox  and  horse  possessed  those  characteristics  which  best 
fitted  them  to  cope  with  the  untoward  conditions  of 
their   environment;     but   there   had   not   yet   appeared 

A  (1) 


2  The   Feeding   of  Animals 

those  specialized  capacities  of  grovvtli,  draft,  speed  or 
production  which  now  render  these  animals  so  very 
valuable  for  the  service  and  sustenance  of  the  human 
family. 

The  qualities  developed  were  those  demanded  by  the 
necessities  of  existence  without  reference  to  utility  as 
measured  by  the  needs  of  a  higher  form  of  life.  The 
fiber  of  the  body  must  possess  endurance,  and  it  mat- 
tered little  whether  or  not  the  muscle  could  furnish  a 
juicy  steak.  The  brute  mother  must  defend  her  young 
and  supply  it  with  milk,  and  this  being  accomplished,  her 
maternal  functions  ceased.  She  was  neither  so  endowed 
that  she  could  open  the  fountains  of  her  life  to  feed 
generously  a  not  too  grateful  master,  nor  so  submissive 
that  she  would.  The  wild  horse  must  be  fleet  and  en- 
during that  he  might  escape  the  enemy,  but  not  that 
he  might  bear  heavy  burdens  or  win  a  contest  in  the 
prescribed  form  of  the  race- track. 

In  the  lapse  of  centuries  there  have  been  many 
changes  in  the  relation  of  man  to  the  animal  creation. 
Bird  and  beast  in  various  forms  have  come  to  minister 
to  man's  wants,  and  in  their  present  domesticated  con- 
dition are,  in  their  turn,  utterly  dependent  upon  him 
for  the  food  and  shelter  which  are  necessary  to  their 
physical  welfare,  or  even  existence.  It  is  not  too  much 
to  assert  that  the  domestic  animal,  in  the  artificial  en- 
vironment imposed  upon  it,  is  entirely  at  man's  mercy, 
even  in  the  development  of  those  attributes  and  char- 
acteristics which  otherwise  would  be  determined  by  the 
demands  of  an  unaided  warfare  with  nature.  The  juicy 
sirloin   of    the   shorthorn,    the   almost   abnormal   milk 


Man  Improves  the  Animal  3 

glands  of  the  champion  butter  cow,  the  delicate  fiber  of 
merino  wool,  and  the  marvelous  speed  of  the  modern 
race-horse  are  evidences  of  man's  skill  in  recasting 
natural  types  into  forms  of  greater  usefulness  to  him. 
From  the  animal  of  nature,  under  the  direction  of  a 
higher  intelligence,  has  proceeded  the  animal  of.  civil- 
ization, an  organism  obedient  to  the  environment  which 
has  been  created  for  it. 

This  interdependence  of  man  and  the  lower  orders 
of  life  has  a  vast  economic  significance.  A  large  part 
of  human  activity  is  devoted  to  the  production  and 
transportation  of  food  for  animals  and  to  the  traffic  in 
the  products  of  the  dairy,  slaughter-house  and  sheep- 
fold,  and  to  their  utilization  in  various  ways.  The 
l^rosperity  of  every  farm  is  maintained  to  a  greater  or 
less  extent  by  feeding  domestic  animals,  and  our  rail- 
roads, our  markets,  in  fact,  nearly  all  our  important 
business  enterprises,  are  more  or  less  dependent  upon 
the  extent  and  prosperity  of  animal  husbandry. 

THE   CONDITIONS   AND   PROBLEMS    INVOLVED    IN 
FEEDING  ANIMALS 

The  first  and  simplest  form  of  animal  husbandry  is 
that  which  was  practiced  by  the  nomad.  His  flocks 
and  herds  subsisted  wholly  by  grazing  and  were  moved 
from  place  to  place  according  to  the  supply  of  forage 
afforded  by  different  localities.  No  shelter  was  pro- 
vided for  the  animals  and  no  food  was  stored  for  their 
use.  The  only  intelligence  or  special  knowledge  that 
was  brought  to  bear  upon  the  business  of  the  herdsman 


4  The  Feeding  of  Animals 

was  a  familiarity  with  the  traditions  and  superstitions 
touehing  the  care  of  cattle  and  the  acquaintance  which 
a  roving  life  would  give  with  the  pastures  furnishing 
the  most  abundant  and  sweetest  wild  grasses  during  the 
various  seasons  of  the  year.  There  was  not  then  even 
a  dim  promise  of  the  modern  traffic  in  meats  or  of 
the  fine  art  of  dairying  as  we  now  know  it.  As  man 
began  to  give  up  this  wandering  life,  erect  permanent 
dwellings  and  confine  his  ownership  of  land  to  definite 
limits,  he  acquired  the  art  of  tillage,  not  only  that  he 
might  have  food  for  his  family  but  also  for  his  cattle. 
He  then  began  to  store  fodder  in  stacks,  and  later  in 
barns,  to  meet  the  demands  oi:  the  inclement  portions 
of  the  year. 

For  centuries,  however,  grazing  was  the  chief  de- 
pendence for  securing  the  production  of  meat  and  milk 
because  the  foods  supplied  during  the  cold  season  were 
not  in  such  abundance  or  so  nutritious  as  to  sustain 
continuous  growth  or  milk  secretion.  Even  within  the 
remembrance  of  men  now  living,  live  stock  was  not  ex- 
pected to  produce  an  increase  during  the  winter  months 
but  was  simply  maintained  from  autumn  until  spring 
in  order  that  profits  might  be  realized  from  summer 
pasturage.  Formerly  the  demands  of  the  market  were 
much  simpler  than  they  are  now.  Butter  and  cheese 
were  produced  almost  wholly  from  summer  dairying, 
and  no  such  variety  of  fresh  meats  was  offered  to  con- 
sumers dui'ing  the  entire  yeav  as  is  now  the  case.  But 
great  changes  have  occurred  during  the  last  fiftj^  years, 
more  especially  during  tlie  past  twenty-five.  First  of 
all,  we  have  a  modern  t.ype  of  animal,  greatly  unlike  that 


The  Animal  of  Civilization  5 

of  previous  times.  The  ideal  dairy  cow  of  to-day  is  a 
high -pressure  milk  maehiue  extremely'  sensitive  to  her 
environment  and  demanding  a  degree  of  care  in  manage- 
ment and  feeding,  if  she  is  to  do  her  safe  maximum 
work,  which  was  not  necessary  with  coarser  and  less  deli- 
cate organisms.  Every  successful  dairyman  must  noAV 
provide  proper  winter  quarters  for  his  herd  and  through- 
out the  entire  year  must  supply  rations  that  will  sup- 
port continuous,  generous  production.  He  must  do 
this,  too,  by  the  use  of  a  greater  variety  of  foods  than 
was  formerly  available.  Not  only  has  the  number  of 
useful  forage  crops  greatly  increased,  but  the  average 
farmer  no  longer  produces  all  the  food  which  his  ani- 
mals consume.  He  now  buys  numerous  kinds  of  com- 
mercial feeding  stuffs.  These  purchased  materials  are 
not  wholly  the  cereal  grains  whose  value  through  long 
experience  has  come  to  be  measured  by  certain  prac- 
tical standards,  but  they  consist  in  part  of  compara- 
tively new  by-products  from  the  manufacture  of  oils, 
starch  and  human  food  preparations, — feeding  stuffs 
which  differ  greatly  in  their  nutritive  properties.  Be- 
sides all  these  changes,  animal  husbandry  is  now  called 
upon  as  never  before  to  feed  the  prosperous  part  of 
humanity  with  high -class  products  having  special  qual- 
ities of  texture  and  flavor  that  depend  to  some  extent 
upon  feeding.  Certainl}^  the  conditions  and  problems 
to  be  met  in  this  branch  of  human  industry  have  grown 
more  and  more  complex. 

We  must  add  to  this  the  fact  that,  as  is  true  with 
every  department  of  man's  activity,  science  has  laid 
her  hands  upon  the   business  of   the  farmer  and   has 


6  The  Feeding  of  Animals 

forced  him  into  a  new  range  of  thought  and  practice. 
This  influx  of  knowledge  has  greatl}^  influenced  the 
requirements  for  meeting  a  sharpened  competition  and 
has  rendered  it  imperative  for  the  practitioner  to  bring 
to  bear  upon  a  great  variety  of  agricultural  problems 
a  clear  understanding  of  fundamental  facts  and  prin- 
ciples. 

The  feeding  of  animals  involves  many  difficult  ques- 
tions. These  begin  with  the  production  of  forage  and 
grain  crops  where  it  is  necessary  to  discover  what  ones 
will  yield  the  largest  food  values  per  unit  of  expendi- 
ture. Economy  demands  that  the  several  feeding  stuff's 
which  are  at  command  shall  be  so  combined  that  there 
shall  be  no  waste  of  material  or  energy.  With  several 
considerations  in  view,  a  decision  must  be  reached  as 
to  the  most  profitable  commercial  foods  to  purchase 
when  the  number  is  large  and  the  range  of  prices  is 
wide.  The  influence  of  the  various  foods  upon  the 
quality  of  the  product,  especially  dairy  products,  has 
in  recent  years  become  an  important  matter.  These 
and  related  problems  confront  the  stockman  and  dairy- 
man, and  they  demand  for  their  wise  solution  more  than 
what  is  ordinarily  designated  as  practical  experience. 
The  investigator  who  shall  successfully  inquire  into 
these  matters  must  possess  scientific  qualifications  of 
a  high  order;  and  the  practical  man,  who,  in  a  busi- 
ness way,  conforms  his  methods  to  the  highest  stand- 
ard which  scientific  research  has  already  made  possible 
must  be  familiar  w^ith  the  knowledge  fundamental  to 
the  feeder's  art. 


CHAPTER   II 

THE   RELATIONS  OF  PLANT  AND  ANIMAL   LIFE 

The  foundations  of  animal  life  are  laid  in  the  plant, 
and  with  the  plant  must  begin  a  study  of  the  funda- 
mental facts  of  animal  nutrition.  The  first  step  toward 
supplying  animals  with  food  is  taken  w^hen  the  farmer 
drops  seed  into  the  warm  earth.  As  soon  as  the  j'oung 
rootlets  from  a  germinating  seed  come  in  contact  with 
the  soil  and  the  first  leaves  reach  the  air,  assimilative 
growth  begins.  During  the  hours  of  sunlight  matter 
is  constantly  gathered  in  an  invisible  way,  which,  after 
transformation  into  various  compounds,  is  added  to  the 
enlarging  tissues  of  the  plant.  This  continues,  per- 
haps for  a  season,  until  the  stalk  of  grain  has  reached 
its  full  height  and  has  attained  the  ultimate  object 
of  its  existence  in  the  production  of  seed,  or  it  may 
go  on  for  centuries,  so  that  where  now  is  only  the 
acorn  there  will  be  the  giant  oak.  The  farmer  car- 
ries to  the  field  a  few  pounds  of  seed  and  he  returns 
to  his  storehouses  laden  with  tons  of  new  material, 
perhaps  hay,  perhaps  grain.  From  somewhere,  in  some 
way,  the  plant  has  gathered  various  substances,  often 
no  less  than  ten  thousand  pounds  per  acre  in  a  single 
year,  and  has  manufactured  them  into  forms  that  are 
useful  to  the  husbandman. 

(7) 


8  The  Feeding  of  Animals 

Plant  life  not  only  bnilds  tissue:  it  stores  energy, 
as  we  may  easily  discover.  The  fanner's  boy  learns 
this  when  he  feels  the  hot  glow  of  the  fire  that  is 
fed  by  forest  wood.  The  wood  disappears,  but  he  is 
warmed  by  the  radiant  energy.  It  has  occurred  that 
when  fuel  was  scarce  and  costly  and  grain  was  abun- 
dant and  cheap,  the  western  farmer  has  burned  his 
corn.  All  he  realized  in  this  case  for  his  labor  was 
the  warmth  which  w^as  necessarj'  to  make  himself  and 
family  comfortable.  As  with  the  wood,  the  materials 
which  were  collected  from  the  soil  and  air  have  been  dis- 
persed in  invisible  forms  during  the  combustion  which 
liberated  the  heat  energy,  except  a  small  heap  of  ashes 
on  the  hearth.  The  farmers  who  raised  corn  for  fuel 
were  no  richer  in  storehouse  or  in  pocket.  They  had 
simply  used  an  available  supply  of  heat,  derived  from 
the  energy  which  was  stored  in  the  plant  during  its 
growth. 

But  ordinarily,  grass  and  grain  are  produced,  not 
for  fuel  but  for  food  purposes,  and  in  this  use  of  vege- 
table matter  we  come  in  contact  with  a  set  of  plie- 
nomena  equally  complex  and  equally  important  and 
interesting  to  those  of  its  growth.  The  calf  of  to-day 
weighing,  perhaps,  a  hundred  pounds,  becomes  in  a  few 
years  the  immense  bullock.  What  is  the  source  of 
this  mass  of  bone  and  flesh  f  It  is  merely  plant  sub- 
stance which  in  other  combinations  was  collected  from 
soil  and  air.  This  animal  eats  his  daily  ration  and 
makes  his  daily  gain  of  tissue.  When  his  food  is  with- 
hold, his  body  wastes  and  he  dies.  If  his  food  varies 
in  amount,  his  growth  is  somewhat  proportional  to  the 


Tlif  Bole  of  the  Plant  9 

quantity  eaten.  We,  therefore,  cannot  resist  the  con- 
dnsion  that  the  bones,  blood  and  flesh  of  this  ox  are 
derived  from  what  he  eats. 

The  plant  does  more  than  to  supply  building  ma- 
terial for  the  animal  body.  This  living  organism  is 
kept  warm.  No  matter  how  cold  the  surrounding  at- 
mosphere, we  find  by  the  use  of  a  thermometer  that  in 
health  the  ox's  temperature  remains  at  about  101°  F., 
with  but  small  variation.  Just  as  the  western  farmer 
obtained  heat  by  burning  corn  in  the  fireplace,  so  does 
the  cattle -owner  maintain  the  body  temperature  of  his 
animals  at  the  necessary  degree  by  supplj'ing  food  to 
be  burned.  The  combustion  is  not  so  rapid  as  occurs 
in  the  fireplace,  still  the  changes  are  the  same  but  more 
slowly  carried  on. 

Food  not  only  builds  the  ox  and  warms  him, — it 
furnishes  him  with  motive  power.  The  energy  which 
the  plant  acquires  during  its  time  of  growth  is,  through 
his  vital  processes,  transformed  in  part  into  motion. 
The  animal  is  a  living  mechanism,  a  combination  of 
muscles  and  levers  which  are  moved  not  by  means 
of  a  spontaneous  internal  generation  of  energy,  but 
through  a  supply  from  without,  the  energy  stored  in 
the  plant. 

If  we  use  the  plant  for  fuel  we  get  heat  alone;  if 
we  feed  it  to  the  animals  we  get  heat,  motion  and  the 
production  of  other  forms  of  niatter  that  have  a  rela- 
tively high  commercial  value.  In  the  first  instance 
the  plant  substance,  except  the  mineral  portion,  is 
wholly  broken  up  into  simpler  compounds  which  in 
unseen  gaseous  forms  escape  from  our  possession,  the 


10  The  Feeding  of  A^iimals 

liberated  energy  becoming  manifest  as  heat.  With  the 
animal,  a  greatly  varying  proportion  of  the  dry  matter 
of  the  plant  is  retained  to  form  his  body  substance, 
and  the  remaining  part  suffers  decomposition,  largely 
into  the  same  compounds  that  are  carried  away  by  the 
draft  from  the  fire  on  the  hearth.  As  a  result  there  is 
built  a  living  organism  that  is  warmed  to  a  tempera- 
ture generally  much  above  that  of  the  surrounding  air, 
which  is  the  seat  of  complex  internal  activities  and  is 
capable  of  performing  external  work. 


CHAPTER  III 

THE    CHEMICAL   ELEMENTS   OF  ANIMAL   NUTRITION 

The  facts  which  are  fuudamentally  necessary  to  a 
broad  understanding  of  the  economy  of  cattle  feeding, 
pertain,  first  of  all,  to  the  materials  out  of  which  vege- 
table and  animal  tissues  are  constructed.  It  is  impor- 
tant to  know  both  what  these  are  and  what  are  their 
sources. 

About  seventy  substances  are  now  believed  to  be 
chemical  elements,  i.  e.,  substances  that  cannot  be  re- 
solved into  two  or  more  simpler  ones,  and  of  which,  so 
far  as  known,  all  forms  of  matter  are  composed,  the 
varietj"  of  combinations  being  almost  infinite.  It  is 
remarkable  that  comparatively  few  of  these  fundamental 
substances, — about  one -fifth, — are  intimately  related  to 
the  growth  of  plants;  and  those  that  occupy  a  promi- 
nent place  in  animal  nutrition  are  even  less  in  number. 

It  is  necessary  to  mention  only  fifteen  elements  in 
this  connection,  some  of  which  are  of  minor  impor- 
tance: carbon,  oxygen,  hydrogen,  nitrogen,  sulfur, 
phosphorus,  chlorine,  silicon,  fluorine,  potassium,  so- 
dium, calcium,  magnesium,  iron  and  manganese. 

At  ordinary  temperatures,  four  of  these,  oxygen, 
hydrogen,  nitrogen  and  chlorine,  are  gases,  and  the  re- 
maining ones  are  solids.      Four  are  constant  and  im- 

(11) 


12  The  Feeding  of  Animals 

\ 
portant   ingredients   of   the    atmosphere;    viz.,   carbon,    '. 

oxygen,  hydrogen  and  nitrogen,  and  they  also  exist  in  \ 
the  soil  in  gases,  as  well  as  in  combination  in  liquids 
and  solids;  the  other  eleven,  though  sometimes  present 
in  the  air  in  minute  qnantities,  are  found  to  no  appre- 
ciable extent  except  as  fixed  compounds  in  water  and 
in  the  crust  of  the  earth,  or  in  plants  and  animals. 
Nearly  all  of  these  elementary  substances  are  absolutely  j 
essential  to  the  existence  of  animal  life  as  now  con- 
stituted. From  the  standpoint  of  necessity,  they  are, 
therefore,  nearly  all  of  equal  value,  but  if  we  take  into 
consideration  the  relative  ease  and  abundance  of  the 
snpply,  certain  ones  rise  to  a  position  of  supreme  im- 
portance. 

THE   ELEMENTS   AND   THEIR   SOURCES 

Carbon. — This  is  a  familiar  substance  in  common 
life.  Anthracite  coal  and  charcoal  are  examples  of  im- 
pure carbon.  Graphite  in  lead  pencils  is  also  carbon, 
and  so  are  diamonds.  When  wood  chars  or  food  is 
burned  in  an  overheated  oven  the  partially  decomposed 
materials  become  black,  revealing  the  presence  of  car- 
bon, the  other  elements  with  which  it  was  associated 
being  driven  out.  The  humus  of  the  soil  is  vegetable 
matter,  which,  from  other  causes,  has  undergone  some- 
what the  same  change. 

An  immense  quantity  of  carbon  exists  in  the  air, 
combined  with  oxygen  as  carbon  dioxid  or  carbonic 
acid  gas.  The  average  proportion  by  weight  of  tliis 
compound  in  the  atmosphere  is  stated  to   be   .06   per 


Carbon  13 

cent,  and  as  the  weight  of  a  column  of  air  one  inch 
square  is  fifteen  pounds,  it  follows  that  over  every  acre 
of  land  there  is  28.2  tons  of  carbon  dioxid,  or  7.7  tons 
of  carbon.  As  we  know  that  plants  draw  their  supply 
of  this  element  from  the  atmosphere,  and  as  vegetable 
tissue  is  its  only  source  to  the  animal,  we  are  able  to 
assert,  with  confidence,  that  the  carbon  in  the  tissues 
of  animal  life  was  once  floating  in  space. 

A  long  time  ago,  Boussingault  determined  the  aver- 
age yearly  amount  of  carbon  which  was  withdrawn  from 
the  air  by  the  crops  grown  on  a  particular  field  during 
a  period  of  fiv^e  years,  and  found  it  to  be  4,615  pounds. 
This  is  no  more  than  is  acquired  by  a  large  crop  of 
maize.  As  a  matter  of  fact,  plants,  as  well  as  animals, 
contain  a  larger  proportion  of  this  element  than  of  any 
other,  and  the  amount  of  this  substance  which  enters  into 
the  processes  of  growth  and  decay  in  the  vegetable  and 
animal  kingdoms  is  almost  beyond  comprehension.  It 
is  natural  to  wonder  whether  the  atmospheric  supply  is 
equal  to  the  demand.  Any  anxieties  we  may  have  con- 
cerning this  should  be  removed  by  learning  that  during 
many  years  the  percentage  of  atmospheric  carbon  has 
not  changed  appreciably.  The  processes  of  decay  on 
the  earth's  surface,  the  combustion  of  wood  and  coal 
as  fuel  and  of  carbon  compounds  by  animal  life  are  re- 
turning carbon  to  the  air  as  rapidly  as  it  is  being  with- 
drawn. This  is  the  round  traveled, — from  the  air  to 
the  plant,  from  the  plant  to  the  animal,  and  from  the 
animal  back  to  the  air, — a  cycle  in  which  this  element 
has  been  moving  since  life  began,  and  in  which  it  will 
continue  to  move  so  long  as  life  exists. 


14  The  Feeding  of  Animals 

Oxygen. — This  element  is,  next  to  carbon,  the  most 
abundant  component  of  vegetable  and  animal  tissues, 
and  it  stands  second  to  none  in  its  relation  to  the  vital 
processes  of  nearly  all  forms  of  life.  It  is  not  a  sub- 
stance with  which  we  are  familiar  by  sight,  because  we 
ordinarily  come  in  contact  with  it  as  a  transparent, 
colorless  gas.  We  live  and  move  in  it,  for  it  is  an  im- 
portant and  uniformly  abundant  constituent  of  the  at- 
mosphere. The  air  is  over  one-fifth  oxygen  by  volume, 
the  proportion  by  weight  being  slightly  larger.  More 
than  twenty -one  million  pounds  of  this  element  are 
contained  in  the  air  above  a  single  acre  of  land,  a 
quantity  which  remains  remarkably  constant,  and  which 
is  surprisingly  uniform  over  the  entire  surface  of  the 
globe.  While  it  is  being  continuously  withdrawn  from 
the  air  for  the  uses  of  life  and  to  maintain  fuel  com- 
bustion and  processes  of  decay,  it  is,  like  carbon,  as 
continuousl}^  returned. 

Vast  quantities  of  oxygen  are  also  contained  in 
water,  as  this  compound,  which  fills  the  ocean  and 
lakes,  and  is  abundant  in  the  crust  of  the  earth,  is 
nearly  89  per  cent  oxygen.  It  is  estimated  also  that 
the  solids  in  the  ci'ust  of  the  earth  are  one -half  oxy- 
gen. That  which  enters  directly  into  the  uses  of  ani- 
mal life  is,  however,  chiefly  that  which  is  derived  from 
the  atmosphere  and  water. 

Not  a  plant  grows  or  animal  lives  excepting  through 
the  circulation  of  oxygen,  during  which  it  passes  into 
fixed  combinations  and  back  again  to  the  free  form. 
The  animal  uses  the  free  oxygen  in  breathing  and  re- 
turns it  to  the  air  in  part  combined  with  carbon  as  car- 


Oxygen  —  Htjdrogen  15 

bonic  acid,  This  compound  the  plant  appropriates,  re- 
taining the  carbon  for  its  tissues  and  giving  back  the 
uncombined  ox^'gen  to  the  atmosphere  to  be  again 
used  by  animals.  All  decay  and  many  other  chemical 
changes  require  the  presence  of  this  element.  What 
we  speak  of  as  fire  is  due  to  its  union  with  the  ele- 
ments of  the  fuel.  It  bears  an  indispensable  rela- 
tion to  the  mechanical  forces  that  man  now  employs, 
for  it  is  the  agent  which  maintains  combustion  in  the 
furnaces  of  our  industries.  All  the  activities  of  life 
are  intimately  related  to  it.  When  a  plant  grows,  oxy- 
gen is  torn  from  its  union  with  other  elements  by  the 
dominating  power  of  the  sun's  rays,  and  energy  is 
stored  in  vegetable  tissue.  When  this  tissue  is  used  as 
food  the  oxygen  returns  to  its  former  combinations 
through  the  opportunities  offered  by  the  vital  pro- 
cesses of  the  animal,  and  the  hidden  forces  of  the  plant 
compounds  are  thus  manifested  in  a  variety  of  ways. 
The  animal  labors  and  man  toils  and  thinks  because  of 
the  energy  thus  stored  and  liberated. 

Hydrogen. —  This  element,  which,  in  a  free  state, 
is  the  lightest  known  gas,  is  found  abundantly  in  na- 
ture only  in  combination  with  other  elements.  The 
minute  quantities  which  exist  in  the  air  are  due  to 
volcanic  action  and  possibly  to  decay  under  certain 
conditions.  As  a  manufactured  product,  it  has  an  im- 
portant use  in  producing  intense  heat  and  in  filling  bal- 
loons. Hydrogen  constitutes  about  one -ninth  of  water 
by  weight,  and  is  found  in  a  large  number  of  soil  com- 
pounds. It  is  an  essential  constituent  of  vegetable 
and  animal  tissues,  although  it  exists  in  the  compounds 


16  The  Feedmg  of  Animals 

of  living  organisms  in  a  nuicli  smaller  proportion  than 
carbon  or  oxygen.  Plants  obtain  it  largely  from  water, 
and  it  is  fnrnislied  to  the  animal  body  in  water  and  in 
other  compounds. 

Nitrogen.  —  Probably  no  element  has  been  given 
more  attention  in  its  relations  to  agriculture  from  the 
scientific  and  practical  standpoints  than  has  nitrogen 
as  such  and  in  its  compounds.  Like  oxygen  it  is  an 
invisible,  tasteless,  and  odorless  gas  which  forms  in  the 
free  state  a  large  part  of  the  earth's  atmosphere.  The 
air  has  been  considered  to  be  approximately  77  per 
cent  free  nitrogen  by  weight,  but  the  discovery  of  the 
new  element,  argon,  which  has  heretofore  passed  as 
nitrogen,  will  slightly  modify  previous  determinations. 

Nowhere  outside  of  the  air  and  the  tissues  of  living 
organisms  does  nitrogen  exist  in  any  form  in  compara- 
tively large  quantities.  The  soil  spaces  contain  it  and 
it  is  taken  into  solution  in  small  proportions  in  all 
natural  waters.  It  is  found  in  the  mineral,  as  well  as 
organic  compounds  of  the  soil,  but  in  quantities  which 
seem  insignificant  as  compared  with  other  elements, 
such  as  oxygen  and  silicon.  Few  agricultural  soils 
contain  over  one -half  of  one  per  cent  of  combined 
nitrogen.  Minute  quantities  of  its  compounds  exist  in 
the  atmosphere  which  are  being  constantly  carried  to 
the  soil  in  rain-water  and  as  constantly  replaced  by  the 
ammonia  from  decomposing  animal  and  vegetable  mat- 
ter and  by  the  products  of  the  oxidation  of  nitrogen 
through  electrical  action  and  combustion.  Notwith- 
standing this  comparatively  small  supply  of  nitrogen 
compounds,  they  play  a  prominent  part  in  agriculture, 


Nitrogen  17 

both  commercially  and  physiologically.  The  nitrogeu 
balance  of  the  farm  must  be  carefully  considered  both 
by  the  crop  producer  and  by  the  cattle  feeder. 

Nitrogen  compounds  are  especially  important  be- 
cause the  available  supply  is  often  dangerously  near 
the  demand  or  even  below  it.  The  nitrogen  found  in  the 
air  is  inert  for  animal  uses,  and  is  ignored  by  a  large 
majority  of  plants.  Much  of  that  in  the  soil  is  also 
unavailable.  Moreover,  its  immediately  useful  com- 
pounds on  the  farm  are  constantly  subject  to  loss, — 
first  by  processes  of  fermentation  which  the  farmer 
cannot  wholly  prevent,  and  second  by  soil  losses  which 
are  to  some  extent  beyond  control.  Many  of  the  com- 
mercial products  of  the  farm  also  carry  away  much 
nitrogen.  The  sources  of  supply  to  balance  this  outgo 
are  the  nitric  acid  and  ammonia  of  the  rainfall,  the 
free  nitrogen  captured  by  legumes  and  whatever  comes 
from  purchased  fertilizers  and  foods.  These  facts  relate 
primarily  to  plant  production,  but  they  also  sustain  an 
essential  relation  to  the  maintenance  of  animal  life  and 
cannot  be  ignored  in  a  rational  and  well-directed  sys- 
tem of  animal  husbandry. 

Physiologically,  the  nitrogen  compounds  stand  in 
the  front  rank.  They  are  necessary  building  material 
for  the  fundamental  tissues  of  the  animal  and  are  inti- 
mately related  to  the  prominent  chemical  changes  wdiich 
are  involved  in  growth  and  in  the  maintenance  of  life. 
It  is  safe  to  assert,  too,  that  variations  of  these  com- 
pounds in  the  food  may  have  an  important  influence 
on  the  character  of  the  body  structure  or  ou  the 
amount  of  a  particulur  product. 

B 


18  The  Feeding  of  Animals 

As  a  result  of  these  conditions  which  relate  to  the 
supply  of  useful  nitrogen  and  to  its  important  role,  we 
find  that  it  has  assumed  a  prominent  place  in  com- 
merce. It  is  the  most  costly  ingredient  of  fertilizers, 
and  the  value  of  commercial  cattle  foods  is  sometimes 
based  almost  wholly  upon  their  content  of  this  element. 
For  these  reasons,  the  control,  even  though  only  par- 
tial, which  the  farmer  may  now  assume  over  the  in- 
come and  outgo  of  the  nitrogen  compounds  valuable 
to  agriculture  is  a  triumph  of  modern  science,  and  an 
important  feature  of  rural  economy. 

Sulfur  is  a  common  and  familiar  substance.  As  an 
element  it  is  not  widely  distributed  in  nature,  but  its 
compounds  are  found  in  all  soils  and  natural  waters, 
and  in  all  the  higher  forms  of  animal  and  vegetable  life. 
We  know  it  as  "brimstone"  when  fused  in  sticks  and 
as  "flowers  of  sulfur"  when  in  a  finely  divided  form. 
Its  most  common  commercial  compounds  are  sulfuric 
acid  and  the  sulfates  of  potash,  soda,  lime  and  mag- 
nesia. This  element  is  an  essential  part  of  some  of 
the  most  important  tissues  of  the  animal  body,  and  is 
supplied  in  food  in  the  form  of  the  sulfates  and  in  its 
proteid  combinations. 

PhospJwrus  occupies  an  important  place  among  the 
elements  of  nutrition.  In  the  uncombined  form  it  does 
not  exist  in  nature,  as  that  found  in  laboratories  is 
produced  only  by  chemical  means.  Its  compounds  are 
found  everywhere.  The  phosphates  of  calcium,  mag- 
nesium and  iron  are  widely  distributed  in  soils  and 
large  deposits  of  calcium  phosphate  are  known,  from 
which  is  obtained  the  crude  phosphatic  rock  that  serves 


other   Elements  19 

as  a  basis  for  the  manufacture  of  commercial  fertilizers. 
All  feeding  stuifs  in  their  natural  forms  contain  phos- 
phorus, either  as  phosphates,  or  as  combined  in  certain 
nitrogen  compounds  which  stand  in  close  relation  to 
the  vital  processes.  It  is  distributed  in  the  flesh  of 
animals,  and  combined  with  lime  constitutes  a  large 
part  of  bone. 

Chlorine,  which  is  a  constituent  of  common  salt,  is 
essential  to  the  nutrition  of  the  animal.  At  ordinary 
temperatures  it  is,  in  the  free  state,  a  greenish -colored, 
disagreeable  gas.  When  combined  w^th  hydrogen  it 
forms  hydrochloric  acid,  a  compound  which  is  necessary 
to  th3  digestion  of  food.  Any  ordinary  mixed  ration 
contains  this  element  in  a  quantity  sufficient  for  the 
animal's  needs. 

Potassium  combined  with  oxygen  and  hydrogen 
gives  us  the  caustic  potash  of  the  market.  The  ashes 
of  all  plants  contain  this  element,  a  familiar  illustra- 
tion of  this  fact  being  the  potassium  carbonate  leached 
from  wood  ashes  by  hot  w^ater  in  the  old-fashioned  way 
of  making  soft  soap.  The  saleratus  formerly  used  in 
bread -making  is  a  potassium  compound.  This  element 
is  found  in  the  flesh  of  animals,  mostly  in  the  form  of 
the  phosphate,  and  is  abundantly  supplied  for  the  pur- 
poses of  nutrition  by  all  feeding  stuffs  that  are  not 
by-products. 

Sodium  is  the  basal  element  of  common  salt,  and  in 
this  form  it  is  very  generally  supplied  to  domestic  ani- 
mals. In  this  connection,  sodium  chloride  (common 
salt)  is  about  the  only  sodium  compound  we  need  to 
mention,  for  this  is  the  one  that  serves  almost  wholly 


20  The  Feeding  of  Animals 

as  a  source  of  this  element  to  the  animal  whether  it 
is  supplied  directly  as  such  or  is  obtained  from  the 
food.  Sodium  plays  an  important  part  in  the  diges- 
tion of  food,  because  it  is  the  basis  of  certain  bile 
salts  and  is  concerned  in  other  ways  in  the  digestive 
processes. 

Calcium,  when  united  with  oxygen,  forms  lime, 
which  is  one  of  our  commonest  commercial  articles. 
Large  masses  of  lime  rock,  or  carbonate  of  lime,  exist 
in  many  parts  of  the  earth's  surface,  and  every  soil 
contains  more  or  less  of  lime  compounds.  As  com- 
pounds of  this  element  are  usually  found  in  plants  and 
in  the  milk  of  all  animals,  normal  food  nearly  always 
furnishes  a  supply  sufficient  to  meet  the  demands  of 
animal  life.  The  growing  animal  makes  a  generous 
use  of  lime,  because  in  union  with  phosphoric  acid  it  is 
the  chief  building  material  of  the  bony  framework. 
A  deficiency  of  food  lime  is  sure  to  cause  abnormal 
development  of  the  bony  structures.  With  birds,  it 
is  especially  in  demand  during  Qg^  formation,  Qg<^ 
shells   being  mostly  a  lime  compound. 

Iron,  one  of  the  elements  of  living  organisms,  needs 
no  description,  because  its  common  properties  are  fa- 
miliar to  every  one.  Iron  rust  and  iron  ore  are  oxides 
of  this  element,  and  when  the  oxygen  is  removed  from 
these,  we  have  the  bright  gray  metal  of  commerce. 
Though  taken  up  by  plants  and  animals  in  small  quan- 
tities only,  iron  is  absolutely  essential  to  their  growth 
and  welfare,  but  because  of  its  abundance  the  impera- 
tive character  of  the  demand  is  never  realized  in  ordi- 
nary experience. 


Tlie  Elements   in    Plants  21 

PROPORTIONS  OF  THE  ELEMENTS  IN  PLANTS  AND 
ANIMALS 

The  facts  which  have  been  reviewed  coucerning'  the 
elements  out  of  which  the  tissues  of  phints  and  animals 
are  built  are  properly  supplemented  by  a  statement  of 
the  proportions  in  which  these  are  found  in  living  or- 
ganisms. This  information  is  necessary  to  an  under- 
standing of  the  relations  of  supply  and  demand  which 
exist  between  the  vegetable  and  animal  kingdoms  and 
the  raw  materials  of  the  inorganic  world. 

In  Plants. — It  is  estimated  by  a  German  scientist, 
Knop,  that  if  all  the  species  of  the  vegetal)le  kingdom, 
exclusive  of  the  fungi,  were  fused  into  one  mass,  the 
ultimate  composition  of  the  dry  matter  of  this  mixture 
would  be  the  following: 

Per  rent 

Carbon 45 

Oxygen 42 

Hydrogen G .  5 

Nitrogen 1.5 

Mineral  compounds  (ash) 5 

The  composition  of  various  single  species  or  of  parts 
of  a  plant,  such  as  the  fruit  or  straw,  shows  consid- 
erable variations  from  these  average  figures: 

Carbon  Oxygen  Hydrogen  Nitrogen  (Ash) 

Clover  hay 47.4  37.8           5.             2.1  7.7 

Wheat  kernel 46.1  43.4           5.8           2.3  2.4 

Wheat  straw 48.4  38.9           5.3             .4  7.0 

Fodder  beets 42.8  43.4           5.8           1.7  6-3 

Fodder  beet  leaves     38.1  30.8           5.1           4.5  21.5 


22  .      The  Feeding  of  Animals 

Carbon  constitutes  a  larger  proportion  of  the  dry- 
substance  of  plants  than  any  other  element,  and  there 
is  certainly  no  species  that  is  an  exception  to  this  rule. 
Oxygen  stands  next  in  order,  followed  by  hydrogen, 
and  then  nitrogen.  It  is  an  important  fact  in  the 
economy  of  nature  that  those  elements  which,  on  the 
average,  make  up  93.5  per  cent  of  the  dry  matter  of 
plants  have  as  their  main  source  either  the  atmosphere 
or  water.  Only  a  small  percentage  of  the  dry  matter  of 
the  farmer's  crops  is  drawn  from  the  soil,  and  it  there- 
fore follows  that  it  is  this  small  proportion  of  the  mass 
of  matter  that  makes  up  the  inorganic  world  which 
sustains  the  most  important  economic  and  financial 
relations  to  the  farmer's  business. 

The  elements  of  the  ash  vary  somewhat  in  different 
plants.  For  illustration,  their  proportions  in  the  dry 
matter  of  the  maize  plant  in  bloom  are  given  in  this 
connection : 

Per  cent 

Phosphorus 20 

Silicon 51 

Sulfur 07 

Chlorine 29 

Potassium  1.78 

Sodium 19 

Calcium 72 

Magnesium  39 

Iron 10 

Oxygen  combined  with  the  above 1.73 

Total  per  cent 6.04 

In  animals. — We  are  not  ignorant  of  the  propor- 
tions of  the  chemical  elements  in    the   bodies  of    our 


Proportions  of  Chemical  Elemeirts  23 

larger  animals.  LaAves  and  Gilbert,  of  England,  and 
the  Maine  Experiment  Station,  in  this  countrj^  have 
made  analyses  of  the  entire  bodies,  or  nearly  so,  of 
steers  and  other  domestic  animals.  These  results,  com- 
bined with  our  knowledge  of  the  constitution  of  the 
compounds  of  the  animal  tissues,  enable  us  to  calcu- 
late very  closely  the  proportions  of  carbon  and  other 
elements  in  the  entire  body  of  an  ox: 

Fat  ox  Two  steers,  2  yrs.  old 

Lawes  and  Gilbert         Maine  Station 
Per  cent  Per  cent 

Carbon     63  60 

Oxygen 13.8  14.1 

Hydrogen 9.4  9. 

Nitrogen 5.  5.8 

Mineral  compounds  (ash) 8.8  11.1 

As  the  proportion  of  carbon  is  much  larger  in  the 
fats  than  in  the  other  compounds  of  the  animal  l)ody, 
it  is  easj'  to  see  that  the  ultimate  composition  of  the  ox 
would  vary  with  his  condition,  whether  lean  or  very  fat. 
The  figures  given  suffice  to  show,  however,  that  ani- 
mals, like  plants,  contain  much  more  carbon  than  of 
any  other  element,  and  that  the  quantities  of  the  re- 
maining elements  stand  in  the  same  order  in  the  plant 
and  in  the  animal,  the  striking  diiferences  being  the 
greater  proportion  of  oxygen  in  the  former  and  of 
carbon  and  nitrogen  in  the  latter.  The  plant  and  ani- 
mal are  alike,  therefore,  in  consisting  chiefly  of  those 
elements  which  are  derived  from  air  and  water.  Car- 
bon, oxj^gen  and  hydrogen  constitute  from  83  to  86  per 
cent  of  the  bodies  of  fat  oxen  and  steers,  raw  materials 
which  nature  supplies  without  cost  to  the  farmer,  leav- 


24  The  Feeding  of  Animals 

ing  less  than  one-sixth  of  the  animal  to  be  built  from 
elements  that  have,  in  part,  a  commercial  value  for 
crop  production,  which  is  the  fundamental  considera- 
tion in  animal  husbandry. 

As  has  been  stated  previously,  one  of  these  ele- 
ments, which  in  its  various  compounds  bears  a  market 
value,  is  nitrogen.  The  others  having  commercial  im- 
portance belong  to  what  is  termed  the  ash  of  the  plant 
or  animal.  For  this  and  other  reasons  it  is  desirable 
to  consider  the  elements  found  in  the  ash  or  mineral 
portion  of  the  animal  body.  We  will  return  for  this 
information  to  the  analysis  of  a  fat  ox  made  by  Lawes 
and  Gilbert.  These  investigators  found  that  the  ash, 
constituting  8.8  per  cent  of  the  dry  substance  of  the 
entire  body,  was  made  up  as  follows: 

Per  cent 

Phosphorus 1.53 

Calcium 2.80 

Potassium  .  .26 

Sodium 20 

Magnesium 07 

Oxygen,  combined  with  the  above 3.29 

Silicon,  sulfur 65 

8.80 

Of  the  elements  other  than  oxygen  which  appear  in 
the  ash,  phosphorus  and  calcium  take  a  leading  place  as 
to  quantity,  although  sulfur,  potassium  and  sodium  are 
essential,  even  if  present  in  relatively  small  amounts. 
Phosphorus,  potassium  and  calcium  have  a  commercial 
pi'ominence  in  their  agricultural  relations,  a  fact  which 
is  to  be  considered  chiefly  in  their  uses  as  plant -foods. 


CHAPTER   IV 

THE    COMFOUyUS    OF  ANIMAL   NUTRITION 

The  animal  body  consists  primaril}^  of  elements, 
but  we  ordinarily  regard  it  as  made  up  of  componnds. 
These  are  groups  of  elements  united  in  such  fixed  and 
constant  proportions  that  they  have  as  uniform  proper- 
ties, under  given  conditions,  as  the  elements  themselves. 
In  discussing  the  composition  and  uses  of  cattle  foods 
and  the  structure,  composition  and  functions  of  the 
animal  as  an  organism,  we  refer  chiefly  to  the  com- 
pounds of  carbon  rather  than  to  carbon  itself.  To  be 
sure,  the  investigator  of  the  problems  of  nutrition  often 
conducts  his  researches  and  formulates  his  conclusions 
with  reference  to  the  elements,  but  when  the  informa- 
tion he  secures  reaches  the  language  of  practice,  we 
speak  of  albuminoids,  carbohydrates  and  fats.  Com- 
merce recognizes  these  compounds  also.  It  is  necessary, 
therefore,  for  the  student  of  animal  nutrition,  whether 
as  a  scientist  or  as  one  who  would  thoroughly  under- 
stand the  art  of  feeding,  to  become  well  informed  about 
those  substances  that  in  various  proportions  form  the 
organized  structure  of  plants',  and  that  furnish  not 
only  the  energies  that  are  manifested  by  animal  life, 
but  all  the  materials  out  of  which  the  animal  tissues 
are  built. 

(25) 


26  The  Feeding  of  Animals 


CLASSES   OF   MATTER 


Before  passing  to  a  consideration  in  detail  of  the 
proximate  constituents  of  plants  and  animals,  it  is  de- 
sirable to  reach  a  clear  understanding  of  certain  broad 
divisions  into  which  we  classify  all  matter,  either  living 
or  dead,  which  has  been  organized  by  the  vital  forces 
of  the  various  forms  of  life. 

One  of  the  most  common  and  familiar  phenomena 
of  the  phj^sical  world  is  the  destruction  of  vegetable  or 
animal  matter  by  combustion,  with  the  result  that  only 
a  small  portion  of  the  original  material  is  left  behind 
in  visible  and  solid  forms.  Fuel,  such  as  wood  or  coal, 
is  largely  consumed  when  ignited,  and  we  have  as  a 
residue  the  ashes.  If  we  incinerate  hay,  corn  or  wheat 
we  get  the  same  result.  The  gradual  decomposition  of 
exposed  dead  vegetable  matter  that  occurs  in  warm 
weather  is  a  process  essentially  similar  to  the  com- 
bustion of  fuel,  only  more  prolonged.  In  view  of 
these  facts,  it  is  customary  to  classify  all  the  tissues  of 
phmts  and  animals  into  the  combustible  and  incombus- 
tible portions,  the  former  being  that  part  of  the  ignited 
or  decayed  substance  which  disappears  in  the  air  as 
gases,  and  the  latter  the  residue  or  ash.  It  should  be 
well  understood  that  combustion  does  not  involve  a  loss 
of  matter;  only  a  change  into  other  forms.  If  we  were 
to  collect  the  gases  which  pass  off  from  a  stick  of  wood 
that  is  burned,  consisting  mostly  of  carbon  dioxid, 
vapor  of  water,  ammonia  and,  perhaps,  certain  other 
compounds  of  nitrogen,  we  would  find  that  their  total 
weight,  plus   that  of   the  ash  residue,  is  even  greater 


Glasses  of  Matter  27 

than  that  of  the  dry  wood,  because  the  carbon  and  the 
hydrogen  of  the  wood  have  taken  to  themselves  from 
the  air,  during  the  combustion,  an  increased  amount 
of  oxygen.  The  carbon,  ox3-gen,  hydrogen  and  nitrogen 
of  the  phmt  or  animal  tissue  belong  to  the  combusti- 
ble portion,  although  small  amounts  of  two  of  these 
elements  are  found  in  the  ash,  as  it  is  usually  esti- 
mated. The  remainder  of  the  fifteen  elements  previ- 
ously named  are  supposed  to  appear  wholly  in  the  ash. 
The  relation  in  quantity  of  the  combustible  and  in- 
combustible parts  of  vegetable  and  animal  dry  matter 
is  illustrated  below: 

Combustible    Incombustible 
(Asb) 
Per  cent  Per  cent 

Clover  hay 92.8  7.2 

Potato  tubers 95.5  45 

Maize  kernel 98.3  1.7 

Wheat  kernel   98.  2. 

Body  of  fat  ox 91.2  8.8 

The  significance  of  these  facts  in  their  relation  to 
cattle  feeding  is,  that  the  chemical  change  which  we 
call  combustion  is  one  of  the  phenomena  of  animal  nu- 
trition. Substances  which  may  suffer  either  slow  or 
rapid  oxidation  outside  the  animal  may  undergo  com- 
plete or  partial  combustion  in  the  animal;  or,  stated  in 
another  way,  the.  part  of  the  plant  which  "burns  up" 
in  the  fireplace  or  crucible  is  the  part  which  in  general 
undergoes  the  same  change  within  the  animal  organism 
in  so  far  as  the  food  is  digested. 

The  terms  combusti])le  and  incombustible  are  less 
used,  perhaps,  than  two  others,  which  represent  prac- 


28  The  Feeding  of  Animals 

tically  the  same  divisions  of  plant  or  animal  substance; 
viz.,  organic  and  inorganic.  In  chemical  literature, 
the  portion  of  a  plant  or  animal  which  suffers  combus- 
tion is  called  the  organic,  and  the  ash  is  known  as  the 
inorganic  part.  These  terms  are  evidently  based  upon 
the  erroneous  assumption  that  the  compounds  which 
burn  and  break  up  into  simpler  ones  are  peculiarly 
those  which  sustain  necessary  and  vital  relations  to  life, 
and  are  formed  through  the  functions  of  living  organ- 
isms. To  be  sure,  the  dry  substance  of  the  plant  is 
organized  chiefly  by  building  up  compounds  of  carbon, 
oxygen,  hydrogen  and  nitrogen,  which  suffer  combus- 
tion; but  compounds  of  sulfur,  phosphorus,  chlorine, 
potassium,  sodium  and  calcium  are  also  constant  and 
essential  constituents  of  the  juices  and  tissues  of  the 
plant  and  animal;  and,  although  the  latter  elements 
maj^  finally  wholly  appear  in  the  incombustible  part 
or  ash,  they  have,  nevertheless,  sustained  in  other  com- 
binations important  relations  to  nutrition  and  growth. 
It  is  true,  however,  that  the  portion  of  a  food  material 
which  is  commonly  spoken  of  as  organic  embraces  those 
compounds  that  furnish  practically  all  the  energy  which 
is  utilized  by  animal  life  and  much  the  larger  part  of 
the  building  material. 

THE   CLASSES   OF   COMPOUNDS 

The  known  compounds  that  belong  to  life  in  all  its 
forms  ai-e  almost  innumerable,  and  doubtless  many  are 
yet  to  be  discovered.  These  sustain  a  variety  of  re- 
lations  to   human   needs,  some  serving  as  food,  some 


Classes  of  Compounds  29 

as  medicine  and  some  in  the  arts.  It  is  fortunate 
that  comparatively  few  must  be  considered  in  dis- 
cussiug  the  science  and  art  of  cattle -feeding.  More- 
over, it  is  convenient  that  the  compounds  which  play 
a  leading  part  in  animal  nutrition  are  designated,  es- 
pecially for  practical  purposes,  in  classes  rather  than 
singly,  even  though  this  custom  tends  to  more  or  less 
looseness  of  expression  and  definition. 

The  same  classification  is  used  for  the  compounds  of 
both  the  vegetable  and  animal  kingdoms,  and  it  is  now 
customary  to  divide  them  into  the  following  groups: 

Water, 

Ash  (mineral  compounds), 
Protein  (nitrogenous  compounds), 
Carbohydrates  (and  related  bodies), 
Fats  (or  oils). 

In  this  instance,  accuracy  is  sacrificed  to  conven- 
ience. The  class  names  have  come  to  be  regarded, 
more  or  less,  as  representing  entities  having  fixed  prop- 
erties and  functions,  whereas  each  class  contains  numer- 
ous compounds  differing  widely  in  their  characteristics 
and  in  their  nutritive  value  and  office.  Moreover,  these 
terms  have  a  variable  significance  as  used  under  differ- 
ent conditions.  No  one  of  them  except  water  uniformly 
represents  just  the  same  mixture  of  compounds  when 
applied  to  unlike  feeding  stuffs. 

Before  passing  to  a  detailed  description  of  these  com- 
pounds, singly  or  in  groups,  it  will  be  well  to  gain  a 
clear  understanding  of  the  relation  which  the  fifteen  ele- 
mcDts  mentioned  sustain  to  these  classes  of  substances. 
This  can  be  seen  most  readily  by  a  tabular  display; 


30 


The  Feeding  of  Animals 


A  1 1  vegeta 
ble  or  aiii 
mal  matter  . 


Incombustible 
or  inorganic 
matter  .  .  . 


Combustible 
or  organic 
matter   .  .  . 


Water.   .   .   .   -/Oxygen 

\^  Hydrogen 

f  Oxygen 
Sulfur 
Chlorine 
Phosphorus 
Silicon,    Fluorine 

■^^^ <  Potassium 

Sodium 
Calcium 
Magnesium 
Iron 
,  Manganese 

C  Carbon 
Oxygen 

I  Hydrogen 
Protein  ......  Nitrogen 

Sulfur  (generally) 
Phosphorus  (sometimes) 

,  Iron  (in  a  few  cases) 

Carbohydrates  f  Carbon 
and  fats    .  .  i  Oxygen 

L  Hydrogen 


The  ash,  which,  on  the  average,  constitutes  about  oue- 
twentieth  of  the  plant,  and  never  more  than  one-teuth 
of  the  animal,  may  contain  thirteen  of  the  fifteen 
elements,  while  the  larger  proportion  of  living  matter 
consists  mostly  of  the  compounds  of  three  or  four  ele- 
ments, in  no  case  of  more  than  six  or  seven.  From 
this  point  of  view,  it  becomes  strikingly  evident  that 
the  dominant  elements  of  life,  quantity  alone  consid- 
ered, are  those  derived  from  the  air  and  water. 

WATER 


Water  fills  a  very  important  place  in  agriculture. 
It  is  everywhere  present,  generally  in  some  useful  way. 
All  plant  substance,  all  animal  tissue,  foods  and  nearly 


Water  in   Organic  Substance  31 

all  the  material  things  with  which  man  comes  in  contact 
in  his  daily  life  are  made  up  of  more  or  less  water,  or  are 
associated  with  it.  Sometimes  this  is  very  evident,  as 
with  green  plants  or  juicy  fruits.  It  is  not  so  evident 
with  straw  and  cornmeal.  If,  however,  we  submit 
almost  any  substance,  no  matter  how  dry  it  may 
appear,  except  perhaps,  glass  and  metals,  to  the  heat 
of  an  oven  at  212°  F.,  we  find  that  a  material  loss 
of  weight  occurs:  and  if  we  so  arrange  that  whatever 
is  driven  off  is  first  drawn  through  some  substance 
that  entirely  absorbs  the  water  which  has  been  vapor- 
ized, we  learn  that  the  decrease  in  weight  is  nearly  all 
accounted  for  by  the  water  thus  collected. 

This  fact  suggests  to  us  the  chemist's  way  of  deter- 
mining the  proportion  of  water  which  any  particular 
material  contains.  He  weighs  out  a  certain  amount 
of  the  substance  and  then  keeps  it  in  an  oven  at 
212°  F.  for  five  hours  perhaps,  after  which  it  is  re- 
weighed.  The  difference  in  the  two  weights,  or  the 
loss,  is  assumed  to  be  all  water,  and  the  percentage  in 
the  original  substance  is  easily  calculated.  That  por- 
tion of  the  material  which  is  left  behind  after  the  water 
is  evaporated,  we  call  the  dry  substance. 

Water  is  associated  with  plant  and  animal  tissues 
in  two  ways,  hygroscopically  and  physiologically.  It 
is  easy  to  illustrate  the  former  way  by  an  object  lesson. 
If  an  ounce  of  cornmeal  were  to  be  dried  in  an  oven 
as  described,  it  would,  as  stated,  lose  in  weight.  If  it 
were  subsequently  allowed  to  remain  exposed  in  the 
open  air  in  a  barn  or  out  of  doors,  it  would  return 
quite  or  nearly  to  its  original  weight.     The  loss  would 


32  The  Feeding  of  Animals 

be  due  to  water  driven  out,  and  the  gain  to  water  ab- 
sorbed from  the  atmosphere,  which  we  call  hygroscopic 
moisture. 

All  solids  attract  moisture  up  to  a  certain  propor- 
tion, which  varies  with  the  substance  and  with  the 
conditions  that  prevail.  The  surfaces  of  the  particles 
of  matter  are  ordinarily  covered  with  a  thin  film  of 
water,  which  is  thicker  on  a  cold,  wet  day  than  on  a 
warm,  dry  day,  and  so  the  same  quantity  of  hay  or 
grain  weighs  less  at  one  time  than  at  another,  because 
the  percentage  of  hygroscopic  water  varies.  An  equi- 
librium will  always  be  established  between  the  attrac- 
tion of  a  substance  for  moisture  and  the  tension  of  the 
vapor  of  water  in  the  surrounding  air,  which  accounts 
for  the  effect  of  temperature  and  of  the  degree  to 
which  the  air  is  saturated  with  water  vapor.  As 
all  substances  do  not  have  the  same  attraction  for 
.moisture,  therefore,  under  similar  atmospheric  condi- 
tions, one  feeding  stuff  may  retain  more  water  than 
another. 

Water  that  is  held  physiologically  is  that  which  is 
a  constant  and  essential  part  of  living  organisms,  in 
which  relation  it  is  necessary  to  life  and  performs 
certain  important  functions.  These  functions  are  of 
three  kinds:  (1)  The  presence  of  water  in  the  tis- 
sues of  plants  and  animals  gives  them  more  or  less 
firmness  or  rigidity  combined  with  elasticity  ;  ( 2  ) 
water  acts  as  a  food  solvent;  (3)  water  is  the  great 
carrier  of  food  materials  and  of  waste  products  from 
one  part  to  another  of  the  vegetable  or  animal  or- 
ganism, 


Water  in  Plants  33 

Water  in  living  plants. — Water  constitutes  a  large 
proportion  of  the  weight  of  all  living  plants,  especially 
during  the  period  of  active  growth.  The  cured  hay,  as 
any  farmer's  boy  knows,  weighs  much  less  than  did  the 
green  grass  when  it  was  cut,  and  this  loss  in  weight  is  due 
almost  wholly  to  evaporation  of  water  from  the  tissues 
of  the  plant  under  the  influence  of  the  sun  and  wind. 
This  water,  which  is  contained  in  the  tubes  and  inter- 
cellular spaces  of  the  stalk  or  leaf,  is  exactly  the  same 
chemical  compound  as  pure  water  found  anywhere  else, 
and  has  no  more  value  for  the  animal,  excepting  that 
it  is  pure  and  is  not  subject  to  the  contamination  which 
sometimes  occurs  in  streams  and  wells.  There  is  no 
such  thing  as  the  so-called  natural  water  of  plants,  and 
which  has  a  peculiar  nutritive  value  or  function.  Vege- 
tation water  should  be  distinguished  from  sap  or  plant 
juice.  Sap  is  more  than  water;  it  is  water  holding  in 
solution  certain  substances  such  as  sugars  and  min- 
eral salts.  When  the  plant  is  dried,  these  soluble  com- 
pounds do  not  pass  off,  but  remain  behind  as  part 
of   the  dry  matter. 

The  proportion  of  water  in  plants  varies  greatly  in 
different  species,  and  in  the  same  species  according  to 
the  stage  of  growth  or  the  surrounding  conditions. 
These  facts  have  more  importance  than  is  generally 
recognized,  because  the  food  value  of  vegetable  sub- 
stances is  influenced  by  the  proportion  of  dry  matter. 
It  is  always  necessary  to  know  the  percentage  of  water 
in  a  green  plant  before  we  can  estimate  its  worth  for 
feeding  purposes. 

The  variations  in  water  content  of  the  living  tissues 


34  The  Feeding  of  Animals 

of  different  species  of  plants  or  parts  of  plants  is  well 
illustrated  by  the  following  figures : 

Water  in  green  i^lants 

Per  cent 

Pasture  grass  (mixed) 80 

Timothy  grass 61.6 

Oats  (fodder) 62.2 

Rye  (fodder) 76.6 

Sorghum  (fodder) 79.4 

Fodder  corn,  dent,  kernels  glazed 73,4 

Fodder  corn,  flint,  kernels  glazed 77.1 

Red  clover 70.8 

Alfalfa 71.8 

Horse  bean ••    84.2 

Potatoes  (tubers) 78.9 

Beets  (mangels) 90.9 

Turnips  90.5 

Immature  plants  contain  more  water  than  older  or 
mature  ones.  Young  pasture  grass  is  more  largely 
water  than  the  same  plants  would  be  after  the  seed  is 
formed.  This  fact  is  consistent  with  the  very  rapid 
transference  of  building  material  during  the  active 
stages  of  growth.  Analyses  of  samples  of  timothy 
grass  cut  at  the  Maine  State  College  in  1879,  and  at 
the  Pennsylvania  State  College  in  1881  show  the 
marked  influence  of  the  stage  of  growth  upon  the 
water  content  of  the  living  plant: 

Maine  State  College 
Timothy  Percentage  of  water 

Nearly  headed  out 78.7 

In  full  blossom 71.9 

Out  of  blossom 65.2 

Nearly  ripe 63.3 


Water  in  Plants  35 

Pennsylvania  State  College 

Percentage  of  water 

Highly  No 

manured      manure 

Cut  June  6,  heads  just  appearing^ 79.7  76.5 

Cut  June  23,  just  beginning  to  bloom 69.7  69.1 

Cut  July  5,  somewhat  past  full  bloom 61.4  60 

What  is  true  of  timothy  is  probably  true  of  all 
forage  crops  m  the  perfectly  fresh  state.  We  have 
here  an  explanation  of  the  difficulty  of  curing  early 
cut  grass.  When  the  farmer  begins  haying,  at  least 
two  drying  days  are  needed  in  order  to  secure  a 
product  that  will  not  ferment  in  the  mow,  wiiile  later 
in  the  season,  grass  cut  in  the  morning  may  be  safely 
stored  in  the  mow  before  night.  At  the  Maine  State 
College  in  1880,  immature  timothy  grass  lost  56.7  per 
cent  weight  in  curing  and  the  ripe  grass  only  12.9 
per  cent.  The  extreme  succulence  of  immature  corn 
and  other  crops  previous  to  the  formation  of  seed,  is  a 
fact  which  the  dairyman  w^ho  feeds  soiling  crops  must 
consider  if  he  would  uniformly  maintain  a  ration  up 
to  the  desired  standard. 

The  proportion  of  water  in  plants  is  influenced  also 
by  the  lack  or  excess  of  soil  moisture.  The  soil  and 
not  the  atmosphere  is  the  source  of  supply  of  vegeta- 
tion w^ater,  which,  taken  up  by  the  roots,  traverses  the 
plant  and  passes  into  the  atmosphere  through  the 
leaves.  If  the  supply  is  abundant,  the  tissues  are 
constantly  fully  charged,  but  if,  by  reason  of  drought, 
the  soil  becomes  very  dry,  the  outgo  of  water  by  evap- 
oration may  exceed  the  income.  What  farmer  has  not 
seen  his  corn  with  rolled  leaves  during  an  August 
drought !      The  vegetation  water  had  fallen  below  the 


36  The  Feeding  of  Animals 

normal,  or  below  what  was  necessary  to  maintain  the 
tissues  in  their  usual  condition  of  rigidity. 

This  leads  to  the  observation  that  the  water  in  a 
growing  plant  is  that  which  is  in  transit  from  the  soil 
to  the  air.  This  liquid  stream  enters  the  plant  with 
its  load  of  building  materials,  takes  into  solution  the 
compounds  elaborated  in  the  leaves  and  aids  in  trans- 
porting them  to  the  points  of  rapid  growth,  finally 
passing  into  the  air  from  the  surface  of  the  foliage. 
Throughout  the  entire  growing  season,  the  plant  acts 
as  a  pump,  drawing  from  below  through  the  roots  the 
water  which  it  needs  for  various  purposes,  and  dis- 
charging it  into  the  air.  It  was  found  that  in  Wis- 
consin 309.8  tons  of  water  was  evaporated  by  the 
plant  for  each  ton  of  dry  matter  in  the  crop.  Four 
tons  of  dry  matter  per  acre  is  not  an  unusual  product 
with  maize,  requiring  1,239.2  tons,  ox  10.4  inches  of 
water  for  its  growth,  the  equivalent  of  about  five -eigh- 
teenths of  an  average  annual  rainfall.  This  is  a  fact  of 
great  significance  to  the  stock  feeder.  His  success  be- 
gins with  proper  husbanding  of  the  plant -food  resources 
of  the  farm,  of  which  water  is  an  important  factor. 

Water  in  feeding  stuffs.— dxXiXe  foods,  whether  in 
the  green  or  air-dry  condition,  always  contain  more  or 
less  water.  The  proportion  is  greatly  variable,  depend- 
ing upon  several  factors.  With  the  green  foods,  the 
range  of  percentages  is  similar  to  that  of  the  living 
plants  previously  noted.  As,  however,  forage  plants 
are  used  at  varying  lengths  of  time  after  cutting,  and  as 
a  loss  of  moisture  begins  immediately  after  the  plant  is 
severed  from  its  source  of  water  supply,  the  amount  of 


Water  in  Feeding   Stu^s  37 

dry  matter  in  a  green  cattle  food  is  somewhat  uncer- 
tain, unless  a  water  determination  is  made  in  the  ma- 
terial exactly  as  it  is  fed.  In  all  experimental  work 
this  precaution  is  necessar^^  to  accuracy.  Roots  and 
potatoes  contain  a  large  proportion  of  water,  which, 
owing  to  their  structure,  is  slowly  evaporated.  In  a 
cool,  moist  cellar,  their  water  content  will  remain  prac- 
tically unchanged  for  a  long  time.  In  a  warm,  dry  room 
evaporation  occurs  and  they  shrivel  and  lose  weight. 

The  water  content  of  air -dry  foods  varies  with  the 
condition  in  which  they  were  stored,  the  length  of  time 
after  storage  and  the  percentage  of  moisture  in  the  air. 
Early  cut  hay  often  goes  to  the  barn  less  perfectly 
cured  than  the  late  cut,  and  all  hay  dries  out  more 
than  is  generally  realized  during  the  first  few  months 
of  storage.  Concerning  these  points,  the  writer  has  ob- 
tained data  through  experiments  at  the  Maine  State  and 
Pennsylvania  State  Colleges.  Fourteen  lots  of  hay,  some 
early  cut  and  some  late  cut,  were  weighed  when  stored 
and  after  remaining  in  the  barn  for  several  months. 
The  results  follow: 


Early  cut 

Late  cut 

As 
stored 

After 
several 
months 

Per  cent 
loss 

As 
stored 

After 
several 
months 

Per  cent 
loss 

Timothy,  1881.. 

.  3634 

2307 

36.5 

4234 

3390 

19.9 

1882.. 

.  3634 

2556 

29.7 

3802 

3168 

16.7 

1881.. 

.  5000 

3922 

21.6 

5270 

4035 

23. 

1882.. 

.  3570 

3037 

14.9 

4017 

3413 

15. 

Clover,      1882.. 

.   2110 

1215 

42.4 

1520 

1130 

25.6 

Timothy,  1888.. 

.   2815 

2470 

12.2 

2790 

2420 

13.3 

1889.. 

.   5070 

4225 

16.6 

6208 

5086 

18.1 

Average    . 

.24.9  .. 

..18.8 

General  average  loss,  22.2. 


38  The  Feeding  of  Animals 

It  is  probable  that  hay  seldom  loses  less  than  one- 
eighth  of  its  weight  during  storage,  and  often  much 
more. 

As  illustrating  the  variations  in  the  proportions  of 
water  in  hay  due  to  changes  in  air  moisture,  reference  is 
made  to  observations  by  Professor  Atwater.  He  found 
that  dry  hay  hung  in  bags  in  a  barn  varied  in  water  con- 
tent between  7.5  per  cent  and  13.6  per  cent  during  the 
months  of  May,  June  and  July.  Hay  in  large  masses 
would  change  less,  but  would  be  affected,  doubtless,  by 
long  periods  either  of  very  dry  weather  or  very  wet. 

The  proportion  of  moisture  in  coarse  foods  and 
grains  has  much  to  do  with  their  preservation  in  a 
sound  condition.  New  hay  and  grains  when  packed  in 
large  masses  are  subject  to  fermentations,  which  injure 
their  quality  and  diminish  their  food  value.  This  is 
due  to  the  fact  that  sufficient  moisture  is  present  to 
allow  the  growth  of  low  forms  of  life  with  certain  at- 
tendant chemical  changes.  Feeding  stuffs  containing 
20  per  cent  or  more  of  water, — and  this  is  likely  to 
be  the  case  with  clover,  rowen,  field -cured  cornf  odder 
and  stover,  new  oats  and  new  corn, — when  stored  in 
large  quantities  are  almost  certain  to  heat  and  become 
musty  or  moldy,  always  involving  a  loss  of  nutritive 
value,  a  result  wholly  due  to  the  large  proportion  of 
water  present. 

^Yaier  in  the  animal. — Water  is  an  important  and 
abundant  constituent  of  animal  organisms,  from  the 
lowest  to  the  highest  forms.  The  blood,  which  is  from 
one-thirtieth  to  one-twentieth  the  weight  of  the  bodies 
of  farm  animals,  is  at  least  four- fifths  water,  while  the 


Wafer  in  Animals  39 

soft  tissues  have  been  found  to  contain  from  44  per 
cent  to  75  per  cent,  according  to  the  species  and  con- 
dition of  the  animal.  The  most  extensive  and  com- 
plete analyses  so  far  made  of  the  entire  bodies  of 
animals  were  performed  by  Lawes  and  Gilbert  at  Roth- 
amsted,  England.  In  this  country  four  steers  vrere 
analyzed  at  the  Maine  Experiment  Station,  and  in 
the  study  of  human  nutrition  problems  many  determi- 
nations of  water  have  been  made  in  the  carcasses  of 
bovines,  swine,  sheep,  poultry  and  game.  The  figures 
are  as  follows: 

Water  in  entire  body 

Per  cent 

Ox,  well-fed,  Lawes  &  Gilbert 6G.2 

Ox,  half  fat,  Lawes  &  Gilbert 59. 

Ox,  fat,  Lawes  &  Gilbert 49.5 

Steer,  17  months  old,  medium  fat,  M.  E    S 59. 

Steer,  17  months  old,  medium  fat,  ^L  E.  S 5G.3 

Steer,  27  months  old,  fat,  M.  E.  S 51.9 

Steer,  27  months  old,  fat,  M.  E.  S 52.2 

Calf,  fat,  Lawes  &  Gilbert G4.G 

Sheep,  lean,  Lawes  &  Gilbert 67.5 

Sheep,  well-fed,  Lawes  &  Gilbert G3.2 

Sheep,  half  fat,  Lawes  &  Gilbert 58.9 

Sheep,  fat,  Lawes  &  Gilbert  50.9 

Sheep,  very  fat,  Lawes  &  Gilbert 43.3 

Swine,  well-fed,  Lawes  &  Gilbert 57.9 

Swine,  fat,  Lawes  &  Gilbert 43.9 

Chicken,  flesh 74.2 

Fowl,  flesh G5.2 

Goose,  flesh 42.3 

Turkey,  flesh 55.5 

It  is  very  evident  that,  in  general,  considerably  more 
than  half  of  the  weight  of  the  bodies  of  our  domestic 


40  The  Feeding  of  Animals 

animals  consists  of  water,  the  limits  observed  in  all 
species  and  conditions  here  mentioned  being  42.3  per 
cent  and  67.5  per  cent. 

The  percentage  of  water  varies  with  the  species,  age 
and  condition.  Swine  carry  a  notably  small  proportion. 
The  calf's  body,  even  though  fat,  is  comparatively 
watery.  It  is  very  noticeable  that  with  oxen,  sheep  and 
swine  the  lean  animals  contain  a  much  larger  proportion 
of  water  than  the  fat.  This  does  not  mean  that  in  the 
process  of  fattening  the  fat  is  substituted  for  water, 
and  so  expels  it  from  the  organism,  but  that  the  in- 
crease has  a  much  smaller  percentage  of  water  than 
the  body  in  its  original  lean  condition.  This  is  well 
illustrated  by  the  data  from  two  independent  investi- 
gations at  Rothamsted  and  at  the  Maine  Experiment 
Station.  The  former  investigation  showed  that  when 
swine,  sheep  and  oxen  are  fattened  the  increase  con- 
tained from  20  per  cent  to  24  per  cent  of  water,  this 
being  half  the  proportion  found  in  the  entire  bodies  of 
the  lean  animals.  The  Maine  Station  results  established 
the  fact  that  in  the  increase  of  two  steers  from  the  age 
of  17  months  to  27  months,  during  which  time  a  fat- 
tening ration  was  fed,  there  was  42  per  cent  of  water, 
the  bodies  of  the  younger  steers  having  58.2  per  cent. 
It  is  a  common  remark  among  unscientific  people  that' 
beef  from  mature  animals  "spends"  better  than  that 
from  young,  the  same  observation  being  made  in  com- 
paring lean  and  fat  beef.  Modern  investigation  shows 
clearly  that  the  reason  for  this  lies  partly  in  the  differ- 
ence in  water  content.  Drj'"  matter,  and  not  w^ater,  is 
the  measure  of  food  value. 


The  Ash   Contents  41 


ASH 

The  ash  or  mineral  part  of  plants  or  animals  occu- 
pies a  minor  place  in  the  discussions  which  pertain  to 
the  principles  and  problems  of  animal  nutrition.  Much 
is  said  and  written  about  the  carbon  compounds  of 
living  organisms,  but  the  compounds  of  the  mineral 
world,  in  their  relation  to  foods  and  to  the  processes  of 
growth,  are  generally  passed  by  with  brief  comment, 
much  less  than  would  be  profitable.  It  is  certainly 
desirable  to  gain  a  clear  understanding  of  the  combi- 
nations, distribution  and  functions  of  these  bodies. 
Their  importance  as  necessary  constituents  of  foods 
and  animals  is  no  less  than  pertains  to  the  carbon 
compounds,  although  their  scientific  and  commercial 
prominence  as  related  to  animal  nutrition  is  much 
less. 

As  previously  stated,  the  mineral  portion  of  a  plant 
or  animal  is  measured  by  the  ash  or  residue  after  com- 
bustion, the  principal  ingredients  of  which  are  the 
following : 

Acids  Bases 

Hydroeblorie  acid  . . .  .HCI.  Potash K^O 

Sulfuric  acid H,S04  Soda  Na^O 

Phosphoric  acid HoPoOs  Lime CaO 

Silicic  acid SiOo  Magnesia MgO 

Carbonic  acid COo  Iron  oxid Fe203 

Other  mineral  compounds  are  found  in  the  various 
forms  of  vegetable  life,  but  those  mentioned  are  all 
that  we  need  to  discuss  at  length. 

The   acids   and   bases   do   not   exist   in  the   ash  as 


42  The  Feeding  of  Anwials 

shown,  but  they  are  united  to  form  salts,  and  so  we 
have  the  chlorides,  sulfates,  phosphates,  and  carbon- 
ates of  potassium,  sodium,  calcium  and  magnesium. 
These  are  nearly  all  familiar  objects  in  common  life, 
as,  for  instance,  sodium  chloride  (common  salt),  potas- 
sium chloride  (the  muriate  of  potash  of  the  market), 
potassium  sulfate  (the  sulfate  of  potash  of  the  market), 
calcium  sulfate  (of  which  gypsum  or  land  plaster  is 
composed),  calcium  phosphate  (burned  bone  is  chiefly 
this  compound),  potassium  phosphate  (a  compound  of 
phosphoric  acid  and  potash  found  chiefly  at  the  drug- 
gist's) and  calcium  carbonate  (limestone).  It  should  be 
remembered  that  the  compounds  in  the  ash  are  not 
necessarily  those  of  the  plant  or  animal.  During  the 
process  of  ignition,  there  is  a  rearrangement  of  the 
acids  and  bases,  so  that  phosphoric  acid  wdiich  was 
combined  with  potash  in  the  plant  may  be  united 
with  lime  in  the  ash.  Much  of  the  lime  in  the  ash 
is  in  union  w4th  carbonic  acid,  which  in  the  plant 
may  have  been  associated  w^ith  vegetable  acids,  such 
as  oxalic  and  tartaric,  and  part  of  the  sulfur  and 
pliosphorus  of  the  ash  comes  from  the  nitrogen  com- 
pounds. 

These  salts  differ  greatly  in  their  properties.  Some 
are  soluble  in  water,  others  are  not.  To  the  former 
class  belong  all  the  chlorides,  and  the  potassium  and 
sodium  sulfates  and  phosphates.  The  normal  phos- 
phates of  calcium  and  magnesium  are  insoluble  in 
water,  but  soluble  in  various  acids.  These  facts  are 
important  in  showing  w^hat  salts  are  in  solution  in  the 
plant  and  animal  juices,  and  what  effect  leaching  with 


( 


Ash  in  Plants  43 

water  or  other  solvents  would  have  upon  the  inorganic 
portion  of  cattle  foods. 

The  mineral  compounds  of  ])lants. — All  plants  and 
feeding  stuffs  contain  mineral  compounds,  which  are 
important  in  this  connection  because,  excepting  com- 
mon salt,  they  are  the  only  source  of  the  mineral  con- 
stituents of  the  animal  body.  These  are  held  in  the 
plant  tissue  chiefly  in  three  ways;  in  solution  in  the 
juices,  in  crystals  in  the  cells  and  as  incrustations  in 
the  cell  walls.  With  the  exception  of  oxj'gen,  sulfur 
and  phosphorus,  no  ingredient  of  the  ash  has  sus- 
tained, so  far  as  known,  a  structural  relation  to  plant 
growth.  When  the  fresh  plant  substance  is  reduced  to 
an  air -dry  condition,  the  salts  in  solution  become  de- 
posited in  the  tissues  as  solids.  The  mineral  matter 
of  plants  and  feeding  stuffs  is  by  no  means  uniform 
in  composition  and  quantity,  even  in  the  same  species 
or  class  of  materials,  although  in  some  grains  there  is 
a  fair  degree  of  similarity  in  this  respect.  Certain 
factors  cause  variations,  such  as  species,  stage  of 
growth,  fertility,  the  part  of  the  plant,  manner  of 
curing  or  treatment  of  a  feeding  stuff  and  changes  due 
to  manufacturing  processes,  and  the  variations  which 
exist  pertain  'not  only  to  the  amount  of  ash  but  also 
to  its  composition. 

Variations  due  to  species.  —  Different  species  of 
plants,  and  consequently  different  feeding  stuffs,  are 
greatly  unlike  in  their  content  of  mineral  matter.  The 
figures  below  illustrate  this  fact,  further  confirmation 
of  which  may  be  had  by  consulting  the  table  in  the 
appendix: 


44  The  Fepcling  of  Animals 

No  of  Per  cent 

aualys.es  ash 

Mixed  grasses 106  7. 

Timothy  grass 9  6.8 

English  ray  grass 11  12,1 

Red  clover,  in  bloom  113  6.9 

White  clover,  in  bloom 4  7.3 

Seradella,  in  bloom 3  9.8 

Buckwheat 17  8.2 

Potatoes 59  3.8 

Sugar  beets 149  3.8 

Mangel-wurzel 19  7.6 

Turnips 32  8. 

Carrots 11  5.8 

Winter  wheat 110  2. 

Oats 57  3.1 

Summer  barley 57  2.6 

Maize 15  1,4 

Peas 40  2.7 

Field  beans 19  3.6 

It  is  important  to  know  that  these  variations  pertain 
not  alone  to  the  qnantity  of  ash  but  to  the  proportions 
of  compounds  which  it  contains: 

The  mineral  compounds  of  plants  and  feeding  stuffs 

[per  cent  in  the  dry  matter) 

Phos-  Sul- 

Pot-                              Mag-     Iron    phorie  furic  Chlor- 

ash      Soda    Lime    nesia    oxide     adid  acid  Silica        iiie 

Mixed  grasses l.SG      .26        1.11        .48        .11          ..''.O  M  2.             .43 

Timothy  hay 2.;!7      .12          Svo        .22        .00          .80  .19  2.19          .33 

Redcloverinbloom2.21      .13        2.39        .75        .07          .(50  .22  .18          .26 

White  clover 1.57      ..53        2.21     *   .09        .15          .94  .54  .33          .31 

Alfalfa 1.74      .13        3.            .30        .14          .03  .42  .70          .22 

Buckwheat 2.54       .19        3.32      1.09         .12          ..50  .30  .09          .06 

Roots 

Potatoes 2.27       .11          .10        .19        .04          .64  .25  .08          .13 

Sugar  beets 2.03      .34          .23        .30        .04          .47  .10  .09          .18 

Fodder  beets 3.!tO    1.23          .28        .83        .06          .05  .23  .15          .75 

Turnips 3.04       .79          .85         .30         .00         1.02  .90  .15          .41 

Carrots 2.02    1.10          .02        .24        .05          .70  .35  .13          .25 


Ash  in  Plants  45 

Phos-  Sul- 

Pot-  Mag-      Iron    phoric  furic  Chlor- 

Grain           ash     Soda    Lime  nesia    oxide     acid  acid  Silica  ine 

Winter  wheat (31      .04          .06        .24        .03          .93  .01  .0-4 

Oats 56      .05          .11        .22        .04          .80  .06  1.22  .03 

Summer  barley 56      .06          .07        .23        .03          .92  .05  .68  .03 

Maize  kernel 43      .02          .03        .22        .01          .66  .01  .03  .01 

Peas 1.18      .03          .13        .22        .02          .98  .09  .02  .04 

Field  beans 1.51      .04          .18        .26        ,02        1.41  .12  .02  .00 


We  cannot  fail  to  observe  as  we  stndy  these  figures 
that  potash,  lime  and  phosphoric  acid  are  the  promi- 
nent mineral  compounds  of  the  whole  plant,  and  con- 
sequently it  is  with  them  that  we  find  the  important 
variations.  The  true  grasses  differ  from  the  clovers 
and  related  plants  in  containing  much  less  lime  and 
greatly  more  silica,  the  phosphoric  acid  and  potash  not 
being  greatly  unlike  in  the  two  cases.  As  a  source  of 
lime,  then,  the  clover  hay  is  superior.  Potatoes  and 
roots  are  richer  in  potash  and  poorer  in  lime  than  are 
the  coarse  fodders.  The  grains  with  hulls  contain  much 
silica,  and  those  like  wheat  and  corn  but  little.  The 
seeds  of  the  legumes  are  richer  in  potash  and  lime  than 
those  of  the  grasses.  The  maize  kernel  is  especially 
poor  in  lime. 

The  distribution  of  mineral  compounds  in  the  differ- 
ent imrts  of  the  plant. — Because  the  farmer  separates 
his  crops  into  grain  and  straw,  and  the  manufacturer 
goes  farther  and  divides  the  grain  into  parts,  thus 
modifying  the  character  of  feeding  stuffs,  it  is  worth 
while  to  know  just  how  the  mineral  compounds  are 
distributed  in  the  stalk,  leaves  and  fruit,  especially 
of  the  cereal  grain  plants.  A  comparison  of  the  straws 
and  grains  shows  striking  dissimilarities: 


46 


The  Feeding  of  Animals 


Per  cent  in  the  dry  matter 

Wheat 

Total 
ash 

Pot- 
ash 

Soda 

Lime 

Magne- 
sium 

Iron 
oxide 

Phos-       Sul- 

phoric    furic 

acid       acid 

Silica 

Chlor- 
ine 

Straw.... 

.  5.1 

.73 

.07 

.31 

.13 

.03 

.26 

13 

3.62 

.09 

Kernel... 

2. 

.61 

.04 

.06 

.24 

.03 

.93 

01 

.04 

Oats 

Straw.... 

.  7.2 

2.07 

.24 

.50 

.26 

.08 

.33 

23 

3.34 

.31 

Kernel . . . 

.  3.1 

.56 

.05 

.11 

.22 

.04 

.80 

06 

1.22 

.03 

Maize 

Straw 

.  5.3 

1.93 

.06 

.58 

.30 

.12 

.44 

28 

1.53 

.07 

Kernel... 

.   1.4 

.43 

.02 

.03 

.22 

.01 

.66 

01 

.03 

.01 

Peas 

Straw.... 

.  5.1 

1.17 

.21 

1.89 

.41 

.09 

.41 

32 

.35 

.29 

Kernel... 

.  2.7 

1.18 

.03 

.13 

.22 

.02 

.98 

09 

.02 

.04 

111  the  first  place,  the  straws  contain  more  mineral 
matter  than  the  grains.  It  is  very  evident  also  that  in 
the  straws  there  is  much  more  potash,  lime  and  silica 
than  in  the  grains,  while  phosphoric  acid  in  most  cases 
exists  in  larger  proportions  in  the  latter. 

The  roots  and  leaves  of  beets  and  turnips  present  a 
striking  difference  in  mineral  content: 


Per  cent  in  the  dry  matter 

Phos-  Sul- 

Total    Pot-  Mag-      Iron    phoric  furic 

Sugar  beefs     ^^^     ^^^    Soda  Lime    nesia    oxide      acid  acid      Silica 

Roots 3.8      2.03      .34  .23          .30          .04           .47  .16 

Leaves 14.8      3.90    2.05  3.            1.69          .08          .71  .79 

Fodder  beets 

Roots 7.6      3.90    1.23  .28           .83           .06           .65  .23 

Leaves 15.3      4.71    2.98  1.63        1.46          .22        1.  .86 

Turnips 

Roots 8.0      3.64      .79  .85          .30          .06        1.02  .90 

Leaves 11.6      2.73    1.10  3.83         .46          .18         .85  1.09          .45       IM 


.09 
1.51 


Chlor- 
ine 

.18 
1.26 

.75 
2.45 

.41 


There  appears  to  be  a  tendency  for  mineral  com- 
pounds to  accumulate  in  the  leaves  of  plants,  and  leafy 
plants  are,  as  a  rule,  those  which  appropriate  these 
most  freely. 


I 


Ash  in  Feeds  47 

The  ash  of  the  outside  of  the  stem  and  of  the  husks 
of  seeds  is  in  relatively  large  proportions,  due  sometimes 
to  an  excess  of  silica.  Husked  rice  kernels  contain  not 
over  .5  per  cent  of  ash,  while  the  husks  contain  39 
per  cent  or  over. 

Influence  of  manufacturing  processes  on  the  ash  con- 
stituents.— The  cattle  food  market  is  abundantly  sup- 
plied with  the  residues  from  certain  manufacturing  in- 
dustries, such  as  milling,  brewing  and  starch  produc- 
tion. The  most  prominent  waste  product  is  wheat 
bran.  As  this  is  the  outside  of  the  kernel,  we  would 
naturally  expect,  in  view  of  the  previous  statements, 
that  it  would  be  rich  in  mineral  compounds,  and  we 
find  such  to  be  the  case.  The  wheat  kernel  contains 
about  2  per  cent  of  ash,  wheat  bran  about  6  per 
cent  and  wheat  flour  about  .5  per  cent.  Bran  may 
become,  therefore,  an  important  source  of  mineral  com- 
pounds in  the  ration.  In  brewing,  the  kernels  of  barley 
are  subjected  to  a  leaching  process,  which  results  in 
taking  out  the  soluble  mineral  salts,  chiefly  the  salts  of 
the  alkalies,  potash  and  soda,  leaving  behind,  in  part, 
the  compounds  of  lime  and  magnesia.  This  fact  is 
made  clear  by  comparing  the  analysis  of  the  ash  of 
barley  with  that  of  brewer's  grain: 

Partial  composition  of  ash  {per  cent) 

Mag-       Phos. 
Potash      Soda       Lime        nesia        acid 

Summer  barley 56         .06         .07         .23         .92 

Brewer's  grains   •• 15         . —         .64         .45       1.69 

As  a  source  of  phosphoric  acid  and  lime  the  brew- 
.er's  grains  are  more  ^fiicient,  pound  for  pound,  than 


48  The  Feeding  of  Animals 

the  original  barley  grains.  Much  the  same  thing  oc- 
curs in  the  manufacture  of  starch  and  glu(;ose  from 
the  maize  kernel,  as  in  brewing,  for  the  ground  grains 
are  either  treated  with  water  or  with  dilute  acid.  As 
the  salts  in  the  maize  kernel  are  largely  those  soluble 
in  water,  the  gluten  meals  and  feeds,  which  are  the 
residues,  have  a  very  small  proportion  of  ash,  not  over 
half  that  in  the  original  kernel.  Analyses  show  that 
the  potash  is  practically  all  extracted,  and  that  the 
phosphoric  acid  is  materially  diminished. 

The  mineral  compounds  of  animal  todies. — The  min- 
eral compounds  of  animals  are  nearly  similar  in  kind  to 
those  of  plants,  but  are  very  different  in  relative  pro- 
portions. This  is  made  plain  by  a  comparison  of  the 
figures  given  below: 

Ash  in  pUints  and  animals  {per  cent) 

Pot-  Mag-    Phos.     Sul.      Silicic     Clilor- 

Dry  substance   Total      ash      Soda      Limo      nesia      acid      acid      acid         iue 

Timothy  hay  ..  6.8  2.4  .12  .55  .22  .80  .19          2.2            .35 

Maize  kernel  . .  1.4  .43  .02  .03  .22  .66  .01            .03          .01 

Wheat  kernel..  2.0  .61  .04  .06  .24  .93  .01            .04 
Fresh  bodies 

Fat  ox 3.9  .14  .12  1.74  .05  1.56  .01 

Fatsheep 2.9  .14  .13  1.19  .04  1.13  .02 

Fat  swine 1.8  .10  .07  .77  .03  .73 

Potash  is  much  less  prominent  in  the  composition 
of  the  animal  than  is  the  case  with  plants,  and  phos- 
phoric acid  and  lime  are  much  more  so.  In  general, 
more  than  80  per  cent  of  the  ash  of  the  animal  body 
consists  of  phosphoric  acid  and  lime  in  combina- 
tion as  calcium  phosphate,  whereas  these  two  com- 
pounds  constitute   less   than   one-fifth   of   the   ash   of 


I 


Ash  in  Animal  Bodies  49 

hay  and  less  than  one- half  of  the  ash  of  maize  and 
wheat  kernels. 

The  distnbution  of  inorganic  compounds  in  the  animal 
body. — The  bones  contain  a  very  large  proportion  of 
the  ash  constitnents  found  in  the  animal  body,  the  soft 
parts  being  poor  in  mineral  salts.  Usually  the  ash 
makes  up  between  60  and  70  per  cent  of  bone,  and  the 
bony  framework  is  from  6  to  9  per  cent  of  the  entire 
bodies  of  domestic  animals.  More  than  80  per  cent 
of  the  ash  of  bone  is  calcium  phosphate,  w^hich  is  asso- 
ciated with  calcium  carbonate,  calcium  fluoride,  calcium 
chloride  and  magnesium  phosphate. 

The  bones  of  all  species  of  animals  show  a  remark- 
able similarity  of  composition,  the  average  of  which 
would  not  be  far  from  the  following: 

In  100  parts  of  the  ash  of  bone  [average) 

Calcium  phosphate 8:5  9 

Calcium  carbonate 13. 

Calcium  in  other  combinations ?>7) 

Fluorine 23 

Chlorine 18 


97.66 


The  muscular  tissue  and  other  soft  parts  of  the  animal 
body  contain  less  than  1  per  cent  of  incombustible 
bodies.  The  ash  of  flesh  is  mostly  phosphoric  acid  aud 
potash,  accompanied  by  comparatively  small  amounts 
of  soda,  lime  and  magnesia  and  minute  quantities  of 
chlorine  and  iron.  Unquestionably,  potassium  phos- 
phate is  the  predominating  salt  in  flesh,  as  calcium 
phosphate  is  in  bone. 


50  The  Feeding  of  Animals 

The  blood  contains  a  variety  of  mineral  substances, 
the  chief  of  which  is  sodium  chloride,  or  common 
salt,  although  a  minute  amount  of  iron  is  present, 
having  a  most  important  function.  In  the  bile,  soda 
is  abundant,  combined  mostly  with  the  peculiar  or- 
ganic acids  of  this  secretion.  Chlorine  is  a  constant 
constituent  of  the  gastric  juice,  its  presence  as  chlor- 
hj'dric  acid  being  essential  to  digestion.  The  preceding 
are  some  of  the  prominent  facts  concerning  the  inor- 
ganic compounds  of  the  animal  body,  but  they  are  only 
a  brief  suggestion  of  the  knowledge  Avhich  pertains  to 
this  part  of  animal  chemistr}'. 


CHAPTER   V 

THE    COMPOUNDS    OF  ANIMAL   NUTRITION,    CONTINUED 
—  THE  NITROGEN   COMPOUNDS 

The  nitrogen  componnds  of  the  vegetable  and  ani- 
mal kingdoms  have  received  much  attention  from  scien- 
tific investigators  and  writers  during  the  past  fifty 
years.  It  is  quite  the  custom  to  declare  "that  certain 
members  of  this  class  of  substances  are  the  ones  most 
important  in  the  domain  of  animal  nutrition,  and  many 
writers  give  to  protein  so  prominent  a  place  in  dis- 
cussing the  relative  value  of  feeding  stuffs  as  to 
almost  ignore  the  other  nutrients.  Certain  investi- 
gators claim,  on  the  other  hand,  that  from  the  stand- 
point of  results  in  practice  the  function  and  relative 
value  of  protein  have  been  unduly  magnified.  What- 
ever may  be  the  correct  view  concerning  these  antago- 
nistic opinions,  it  is  very  evident  that  the  present 
tendency  is  towards  a  fuller  discussion  of  the  office 
and  value  of  the  non- nitrogenous  bodies. 

There  can  scarcely  be  any  disagreement,  however, 
concerning  the  general  proposition  that  protein  plays 
a  leading  part  in  the  processes  and  economy  of  animal 
nutrition.     This  is  true  for  several  reasons: 

(1)  The  nitrogen  compounds  are  those  fundamental 
to  the  energies  of  the  living  cells  which  make  up  the  tis- 

(51) 


52  The  Feeding  of  Animals 

sues  of  plants  and  animals.  The  basic  substance  of  the 
active  cell  is  protoplasm,  a  complex  nitrogenous  body, 
which  Huxley  called  "the  physical  basis  of  life."  Around 
this  primal  substance  seem  to  center  all  vital  activities, 
especially  the  transformation  of  the  raw  materials  of  the 
inorganic  world  into  the  organized  structures  of  life. 

(2)  These  compounds  are  structurally  essential  to 
the  growth  of  living  tissues  and  to  the  formation  of 
milk.  The  significance  of  this  fact  is  intensified  by 
their  paucity  in  many  of  the  feeding  stuffs  that  are 
ordinarily  produced  on  the  farm. 

(3)  Nitrogen  combinations  suitable  for  use  as  plant 
and  animal  food  have  reached  a  position  of  great  com- 
mercial importance.  They  are  the  most  costly  of  all 
the  plant-building  materials,  the  significance  of  which 
is  intensified  by  their  scarcity  in  the  soil  in  useful 
forms,  and  by  their  easy  passage  bej^ond  reach  either 
through  chemical  changes  which  liberate  the  nitrogen, 
or  through  leaching  from  the  soil.  Nitrogenous  feed- 
ing stuffs  also  bear  relatively  high  market  prices. 

PROTEIN 

For  the  sake  of  brevity  and  convenience,  the  nitro- 
gen compounds  of  cattle  foods,  both  vegetable  and 
animal,  are  designated  as  a  class  by  the  single  term 
protein.  When,  therefore,  it  is  stated  that  a  feeding, 
stuff  contains  a  certain  percentage  of  protein,  refer- 
ence is  made  to  the  total  mass  of  nitrogen  compounds 
present,  which  may  be  many  in  number  and  of  greatly 
differing  characteristics. 


Protein  53 

It  should  be  stated,  b}^  way  of  preliminary  explana- 
tion, that,  in  the  past,  the  proportion  of  protein  (total 
nitrogen  compounds)  in  a  feeding  stuff  has  been  ascer- 
tained by  determining  the  total  amount  of  nitrogen 
and  then  multiplying  its  percentage  number  by  the 
factor  G.25.  This  method  is  based  on  the  assumption 
that  the  average  percentage  of  nitrogen  in  protein  com- 
pounds is  sixteen,  which  is  not  true  to  so  close  a  de- 
gree of  approximation  as  was  formerly  believed  to  be 
the  case.  It  may  happen  in  some  instances  that  a 
determination  made  in  this  way  is  sufficiently  accurate, 
while  in  other  cases  the  margin  of  error  is  large.  Re- 
cent investigations  with  perfected  methods  show  per- 
centages of  nitrogen  in  the  numerous  single  proteid 
substances  found  in  the  grains  ranging  from  15.25  to 
18.78.  These  are  largest  in  certain  oil  seeds  and  lu- 
pines and  smallest  in  some  of  the  winter  grains.  Ritt- 
hausen,  a  prominent  German  authority,  concedes  that 
the  factor  6.25  should  be  discarded,  and  suggests  the 
use  of  5.7  for  the  majority  of  cereal  grains  and  legu- 
minous seeds,  5.5  for  the  oil  and  lupine  seeds,  and  6.00 
for  barley,  maize,  buckwheat,  soja  bean,  and  white 
bean  (Phaseolus),  rape,  and  other  brassicas.  Nothing 
short  of  inability  to  secure  greater  accuracy  justifies 
the  longer  continuance  of  a  method  of  calculation 
which  is  apparently  so  greatly  erroneous. 

As  previously  stated,  protein  is  the  accepted  name 
for  a  class  of  compounds.  Just  how  there  came  about 
such  a  grouping  of  a  large  number  of  substances  under 
a  single  head  it  is  not  necessary  to  consider  in  this  con- 
nection, but  it  should  be  made  clear  that  the  individual 


54  Tlie  Feedhig  of  Animals 

compounds  which  are  inchided  under  this  term  are  in 
part  so  unlike  in  chemical  and  phj^sical  properties  as  to 
warrant  the  assertion  that  they  have  nothing  in  com- 
mon except  that  they  contain  nitrogen;  and  we  may 
believe  that  their  unlikeness  in  composition  is  no 
greater  than  the  differences  in  their  nutritive  functions. 

It  is  very  evident  that  it  is  not  only  convenient,  but 
necessary,  to  classify  such  a  heterogeneous  group  of  bod- 
ies into  subdivisions  more  nearly  alike  in  their  charac- 
teristics. When  we  come  to  consider  doing  this  we 
discover  a  most  unfortunate  confusion  of  terms.  Our 
leading  chemists  evidently  have  reached  no  agreement 
in  this  matter,  and  so  we  find  almost  as  many  ways  of 
dividing  the  nitrogenous  compounds  of  plant  and  ani- 
mal life  as  there  are  prominent  writers. 

Nevertheless,  some  system  of  classification  must  be 
used  in  this  connection,  and  perhaps  none  is  more  con- 
venient or  logical  than  the  one  reported  by  a  commit- 
tee on  nomenclature,  representing  the  Association  of 
Agricultural  Colleges  and  Experiment  Stations. 

The  classification  given  here  is  essentially  this  one, 
although  there  are  included  in  it  certain  distinctions 
very  clearly  set  forth  by  Professor  Atwater  in  a  paper 
associated  with  the  above-mentioned  report. 

In  the  arrangement  adopted  it  is  recognized  that 
certain  nitrogen  bodies  included  under  protein  are  so 
unlike  the  main  and  important  members  of  this  group 
as  to  be  properly  styled  non-proteid.  It  is  also  con- 
ceded that  there  are  simple  or  native  proteids  which 
seem  to  stand  in  the  relation  of  "mother"  sn])stances 
to  a  large  number  of   protein  bodies   that   have   been 


Protein  —  Proffuls 


55 


modified  eitlier  by  various  external  agencies,  or  are  the 
result  of  a  union  of  proteids  with  compounds  of  another 
class.  More  than  all,  the  classification  here  used  seems 
to  be  fairly  well  adapted  to  the  effort  of  making  clear 
to  the  beginner  or  unscientific  reader  this  most  difficult 
division  of  our  subject.  No  apology  is  offered  for  the 
hard  names  that  are  used.  They  are  the  only  ones 
available,  and  as  they  have  the  merit  of  conciseness,  it 
is  hoped  that  in  time  they  will  come  into  an  intelligent 
popular  use.     These  are: 

f  Simple  . . 
Modified, 


Protein.  To- 
tal nitrogen 
compounds  . 


Proteids 


r  Albumins 
<  Globulins 
I      and  allies 


/  Derived 
(  Compound 


-  Non-proteids 


Collagens  or 
gelatinoids 

Extractives 

Amides, 

a  m  i  d  o  , 

acids,  etc. 


Other  nitrogen  compounds  are  included  with  the 
protein  by  the  present  methods  of  estimation,  such  as 
alkaloids  and  nitrates,  but  these  are  so  uncommon  in 
feeding  stuffs,  or  are  present  in  such  small  quantities, 
that  they  may  be  safely  ignored. 

PROTEIN  — THE    PROTEIDS 


Proteids  are  the  main  and  important  nitrogen  com- 
pounds either  in  the  plant  or  in  the  animal.  The  pro- 
tein of  seeds  contains  little  else  than  proteids,  while 
that   of   young   fodder   plants   and   especially  of   roots 


66  The  Feeding  of  Animals 

consists  more  largely  of  non-proteids.  They  are  also 
the  chief  constituents  of  muscular  tissue.  The  chemical 
constitution  of  the  proteids  is  not  definitely  known. 
No  investigator  has  yet  been  wise  enough  to  search  out 
their  manner  of  combination,  but  it  is  generally  con- 
sidered to  be  very  complex.  It  is  believed  that  a  cer- 
tain one  of  these  compounds  holds  in  a  single  molecule 
no  less  than  5,000  atoms.  These  bodies  are  con- 
structed from  the  simpler  ones  of  the  inorganic  world 
through  the  vital  energies  of  plants,  and  they  appar- 
ently must  come  to  the  aninml  fully  organized. 

The  ultimate  composition  of  pi'oteids,  that  is,  the 
proportions  of  the  elements  w^hicli  they  contain,  has 
been  carefully  studied,  and  while  there  are  material 
differences  among  them  in  this  respect,  the  limits  of 
variation  are  not  especially  w4de,  as  can  be  seen  from 
the  following  figures  taken  from  Neumeister: 

Elementary  composition  of  the  ])rot€ids 

Per  cent         Per  cent  Average 

Carbon 50.  to     55.  52. 

Hydrogen G.5  to       7.3  7. 

Nitrogen 15.  to     17.6  16. 

Oxygen 19.  to     24.  23. 

Sulphur 3  to       2.4  2. 

We  see  that  the  number  of  elements  ordinarily  found 
in  the  proteids  is  five,  nitrogen  and  sulphur  being 
those  that  chiefly  distinguish  tliese  bodies  from  all' 
others  which  make  up  the  mass  of  combustible  matter. 
Two  other  elements  are  occasionally  involved,  as,  for 
instance,  the  phosphorus  of  casein  and  the  iron  of 
blood. 


I 


Protein — Albuminoids  57 

These  proteids  are  familiar  objects  on  the  farm,  and 
their  properties  are  matters  of  common  observation. 
When  the  farmer's  boy  secures  the  tenacious  cud  of 
gum  from  the  fresh  wheat  gluten,  or  when  the  house- 
wife watches  the  strings  of  coagulated  albumin  sepa- 
rate from  the  cold  water  extract  of  fresh  lean  beef  that 
is  brought  to  the  boiling  point,  or  observes  the  white 
of  an  egg  harden  into  a  tough,  white  mass  as  it  is 
dropped  into  boiling  water ;  when  we  observe  the 
stiffening  of  the  muscular  tissue  of  the  slaughtered 
animal  or  the  rapid  formation  of  strings  of  fibrin  in 
the  cooling  blood;  —  in  all  these  instances  there  are 
manifested  certain  chemical  or  physical  properties  which 
pertain  to  these  most  important  and  useful  com- 
pounds. 

The  alhuminokls.—Oi  all  the  nitrogen  compounds, 
these  exercise  the  most  general  and  prominent  func- 
tions in  plant  and  animal  life.  They  not  only  make  up 
a  large  part  of  the  protein  of  feeding  stuffs,  but  their 
office  in  the  nutrition  of  animals  is  definitely  under- 
stood to  be  of  the  most  important  kind. 

As  has  been  indicated,  the  albuminoids  are  regarded 
as  divisible  into  groups,  the  individuals  of  each  group 
having  certain  distinguishing  common  properties.  The 
two  subdivisions  whose  members  are  most  common 
and  widely  distributed  are  the  albumins  and  globulins. 
Among  these  and  their  derivatives  and  compounds  we 
find  albumin,  mj'osin,  fibrinogen,  albuminates,  pro- 
teoses, peptones,  casein  and  nuclein, — a  formidable  lot 
of  names  whose  use  seems  necessary  to  a  statement  of 
the   facts   we  wish   to  discuss.     It   is   hoped   that   the 


58  The  Feeding  of  Animals 

following  explanations  will  clothe  them  with  practical 
meaning. 

(1)  The  albumins.  There  are  several  albumins. 
They  are  found  in  the  juice  of  plants,  in  certain  liquids 
of  the  animal  body  such  as  the  serous  fluids,  in  muscle, 
blood  and  milk,  and  abundantly  in  eggs.  Unlike  other 
proteids,  these  compounds  are  soluble  in  pure  cold 
water,  and  when  such  a  solution  is  heated  to  the  boil- 
ing point,  they  separate  from  the  liquid  by  coagulation 
and  become  insoluble  unless  acted  upon  by  some  strong 
chemical. 

When  macerated  beef  is  treated  with  cold  w^ater 
the  albumin  in  it  goes  into  solution,  and  if  this  ex- 
tract is  boiled  to  make  beef  tea,  it  is  a  matter  of  com- 
mon observation  that  the  albumin  separates  in  clotted 
masses.  None  remains  in  the  tea.  It  is  well  for  the 
housewife  to  know  that  all  lean  meat  contains  this 
substance,  which  by  prolonged  treatment  with  cold  water 
may  be  removed  to  the  detriment  of  the  residue,  and 
which,  if  the  exterior  surface  of  the  meat  is  brought 
in  contact  with  boiling  w^ater  at  once,  coagulates  in  the 
outer  laj'Crs  of  the  meat  and  thus  prevents  an  exten- 
sive loss  of  soluble  matter. 

The  clear  serous  fluid  which  is  left  after  removing 
the  clot  from  blood  contains  albumin  which  may  also  be 
coagulated  hy  heat.  After  the  casein  is  removed  from 
milk  by  acid  or  rennet,  the  albumin  of  the  milk  remains 
in  the  whey.  It  is  this  which  in  part  causes  milk  to 
clot  if  brought  to  the  boiling  point.  One  of  the  most 
familiar  examples  of  this  class  of  proteids  is  the  white 
of  an  Qgg,  which,  when  cooking  in  boiling  water,  be- 


I 


Froiein  — Alhnminoids  59 

conies  a  hard,  white,  coagiihited  mass.  Albumin  in 
the  serous  fluids  and  in  blood  is  called  serum -albumin, 
in  milk,  lact-albumin  and  in  eggs,  ova-albumin. 

A  small  proportion  of  the  proteids  of  plants  is 
found  to  be  albumin;  for  instance,  Osborne  found  .6 
per  cent  in  wheat,  .43  per  cent  in  rjT,  .3  per  cent  in 
barley,  .5  per  cent  in  soja  beans,  and  some  in  most 
seeds.  This  possesses  essentially  the  same  characters 
as  the  animal  albumin  described  previously.  Whenever 
a  vegetable  substance  is  leached  with  water,  it  is  prob- 
ably this  proteid  which  would  be  the  first  to  suffer 
removal  or  destructive  fermentation. 

(2)  The  globulins.  It  is  fully  recognized  that  when 
plant  and  animal  tissues  are  treated  with  water  but  a 
small  part  of  the  proteids  dissolve.  If,  however,  we 
add  to  the  water  a  mineral  salt,  especially  common  salt 
(sodium  chloride),  sufficient  to  secure  a  10  per  cent 
solution,  an  additional  and  considerable  amount  of  al- 
buminoids is  extracted.  These  compounds  are  called 
globulins  and  differ  from  the  albumins  in  being  insolu- 
ble in  pure  water  and  in  a  saturated  solution  of  certain 
mineral  salts,  such  as  sodium  chloride.  The  globulins 
form  an  important  part  of  the  proteid  content  of  plants 
and  of  animal  tissues,  both  in  quantity  and  in  having 
a  maximum  nutritive  usefulness. 

In  plants  these  proteids  seem  to  be  especially  abun- 
dant and  widespread.  Our  best  and  most  recent  knowl- 
edge on  this  point  comes  from  investigations  conducted 
in  the  laboratory  of  the  Connecticut  Agricultural  Ex- 
periment Station,  chiefly  by  Osborne.  In  these  re- 
searches  the   seeds   of   fifteen   species    of    agricultural 


60  The  Feeding  of  Animals 

plants  were  studied,  all  of  which  were  found  to  contain 
globulins.  In  some  the  proteids  consisted  largely  of 
these  compounds.  The  percentage  content  in  certain 
seeds  was  determined  approximately: 

Globulins  in  certain  seeds 

Per  cent  Per  cent 

Kidney  bean 20.         Maize 0.4 

Cottonseed  meal..  ..  .   15.8       Lentil 13. 

Peas 10.         Horse  bean   ...  17. 

Lupin 26.2       8oy  bean    Chiefly  globulin 

The  seeds  of  the  legumes,  as  a  rule,  have  the  largest 
proportion  of  these  albuminoids. 

From  present  knowledge,  many  seeds  appear  to  have 
characteristic  globulins  which  are  unlike  in  their  chem- 
ical properties.  These  have  been  given  names  derived 
from  the  general  names  of  the  species  in  which  they 
are  found.  Thus  we  have  amandin  in  almonds,  ave- 
nalin  in  oats,  corylin  in  walnuts,  phaseolin  in  several 
species  of  beans,  glycin  in  the  soy  bean,  maysin  in 
maize,  vicilin  in  horse  beans,  vignin  in  the  cow- pea, 
hordein  in  barley,  and  tuberin  in  the  potato.  One 
globulin  called  edestin  appears  to  be  quite  generally 
distributed  in  the  seeds  of  agricultural  plants,  haviner 
been  found  in  a  larger  number  than  any  other  proteid 
yet  discovered,  including  all  the  cereals,  castor  bean, 
cottonseed,  flaxseed,  hemp,  squash  and  sunflower, 
though  it  is  not  abundant  in  any  one  of  these. 

The  animal  globulins  of  which  we  have  definite 
knowledge  are  those  that  exist  in  the  muscle  and  in 
the  blood.  The  names  which  some  of  them  bear  are 
myosin,    fibrinogen,    paraglobulin,     and,    according    to 


Protein  —  AJhuminoids  61 

some  authors,  vitellin.  If  finely  divided,  well- washed 
muscle  (lean  meat)  is  treated  with  a  10  per  cent  salt 
solution,  first  by  rubbing  it  in  a  mortar  with  fine  salt, 
and  then  adding  enough  water  to  secure  the  proper 
strength  of  solution,  a  globulin  is  dissolved  to  which 
the  name  myosin  has  been  given.  The  view  has  been 
generally  accepted  that  this  compound  does  not  exist 
as  such  in  living  muscle,  but  forms  there  by  coagula- 
tion upon  the  death  of  the  animal.  This  change  has 
been  looked  upon  as  similar  to  the  coagulation  of  blood 
through  the  formation  of  fibrin,  and  is  regarded  as  the 
explanation  of  the  stiffening  of  dead  muscles  (rigor 
mortis).  The  theory  is  held  that  a  "mother"  substance 
exists  in  the  living  muscle  from  which  mj-osin  is  formed 
in  much  the  same  way  as  fibrin  is  developed  in  clottiug 
blood  from  a  preexisting  body,  but  no  single  view  as  to 
exactly  what  occurs  is  fully  accepted.  Thei-e  is,  never- 
theless, a  general  agreement  that  rigor  mortis  is  due 
to  a  clotting  of  the  muscle,  accompanied  by  marked 
chemical  transformations,  one  final  product  being  my- 
osin. The  theory  is  advanced  that  ferments  are  present 
in  the  muscle,  to  the  influence  of  which  these  changes 
are  due,  and  without  which  they  do  not  occur,  but 
proof  of  this  view  is  still  lacking.  In  this  whole  field 
much  is  yet  to  be  learned.  Certainly,  the  chemistry  of 
living  and  dead  muscle  is  most  profound,  and  offers  to 
the  bio- chemist  a  wonderfully  attractive  and  fruitful 
field  of  research. 

Another  prominent  and  remarkable  globulin  is  the 
fibrinogen,  which  is  found  in  the  blood.  It  is  common 
knowledge   that  when   blood  is  drawn  from  the  veins 


62  The  Feeding  of  Animals 

and  cools  it  clots,  a  phenomenon  which  is  nothing  more 
than  the  formation  of  strings  of  fibrin.  Fibrin  as  snch 
is  not  found  in  living  blood,  but  is  one  of  the  prod- 
ucts into  which  fibrinogen  splits  when  exposed  blood 
cools,  probably  because  of  the  influence  of  a  ferment. 
Stranger  than  all  is  the  fact  that  so  long  as  the  blood 
is  retained  in  the  arteries  and  veins,  even  if  the  animal 
dies  and  grows  cold,  this  clotting  does  not  appear. 

Serum  globulin  is  a  collective  name  for  several  glob- 
ulins, which  exist  in  blood  serum  and  in  the  other  fluids 
of  the  animal  body,  such  as  lymph  and  its  allies,  in- 
cluding those  exudations  which  pertain  to  diseased 
conditions,  especially  dropsical. 

One  more  proteid  has  been  generally  classified  as  a 
globulin,  although  differing  in  some  respects  from  the 
other  members  of  this  class.  Reference  is  made  to 
vitellin,  which  is  the  principal  proteid  in  the  yolk  of 
eggs.  It  is  there  intimately  mixed  with  certain  pecu- 
liar phosphorized  bodies,  which  we  shall  notice  later. 

Tlie  modified  albuminoids. — All  of  the  proteids  pre- 
viously noticed  may  properly  be  called  simple,  native 
proteids.  This  characterization  is  appropriate  because 
these  are  the  bodies  that  possess  the  typical  reactions 
and  qualities  of  the  albuminoids  as  a  class,  and  are  the 
principal  ones  found  in  the  normal  tissues  of  plants 
and  animals.  They  are  the  basal  substances  from 
which  others  appear  to  be  derived  after  modifications 
of  one  kind  or  another.  It  seems  proper,  therefore,  to 
speak  of  certain  other  proteids  as  modified  albuminoids, 
because,  through  various  influences,  either  natural  or 
artificial,    they  have   acquired    chemical    and    physical 


Protein  —  Modified   Albuminoids  63 

properties   unlike  those  possessed  by  the  mother  sub- 
stances. 

A  convenient  division  of  these  modified  bodies, 
though  perhaps  not  strictly  scientific,  may  be  made 
in  accordance  with  the  cause  or  manner  of  change. 
These  causes  are:  (1)  coagulating  ferments;  (2)  heat; 
(3)  action  of  acids  and  alkalies;  (4)  the  ferments  of 
digestion;   (5)   combinations  with  other  compounds. 

(1)  Coagulating  ferments.  Reference  has  been 
made  to  that  interesting  phenomenon,  the  coagula- 
tion or  clotting  of  blood.  As  stated,  this  is  now 
known  to  be  due  to  a  formation  of  a  new  compound, 
called  fibrin.  The  mother  substance,  fibrinogen,  and 
not  the  fibrin  exists  in  the  living  blood,  and  it 
seems  to  be  well  proven  that  the  splitting  of  the  fibrin- 
ogen into  two  substances,  one  of  which  is  fibrin,  is 
due  to  the  action  of  a  ferment,  designated  as  a  fibrin 
ferment.  It  would  be  out  of  place  to  review  the  data 
upon  which  this  conclusion  is  based.  There  are,  to 
be  sure,  conflicting  views,  but  the  one  stated  seems  to 
be  the  most  fully  established.  Fibrin,  after  thorough 
washing,  is  an  elastic  white  substance,  which,  in  its 
chemical  properties,  stands  very  close  to  the  albumins 
that  are  coagulated   by  heat. 

It  has  been  held  by  various  investigators  that  other 
changes  in  animal  fluids  and  tissues  are  brought  about 
in  the  same  manner  as  the  formation  of  fibrin,  i.  e.,  by 
the  action  of  a  ferment.  In  one  case,  this  is  certainly 
true,  viz. ;  the  curdling  of  milk  under  the  influence  of 
the  ferment  rennin.  This  ferment,  which  for  cheese- 
making  purposes  is  extracted  from  the  fourth  stomach 


64  The  Feeding  of  Animals 

of  a  calf,  will,  when  added  to  milk  at  a  proper  tem- 
perature, cause  the  coagulation  which  gives  ns  the 
cheese  curd.  The  probable  correct  explanation  of  this 
familiar  phenomenon  is  that  the  casein  is  decomposed 
into  two  other  substances,  one  being  paracasein  and 
the  other  an  albumin,  the  first  of  which  subsequently 
unites  with  lime  salts  in  the  milk  and  forms  the  in- 
soluble substance  that  we  know  as  curd.  The  occur- 
rence of  this  latter  step  appears  to  be  proven  by  the 
fact  that  in  the  absence  of  lime  salts  no  curd  forms, 
but  it  immediately  appears  when  such  salts  are  added 
to  the  lime-free  solution.  As  milk  always  contains 
sufficient  lime  to  make  coagulation  possible,  this  ex- 
planation of  the  coagulation  of  casein  has  chiefly  a 
scientific  interest. 

Mention  has  been  made  of  the  clotting  of  dead 
muscle,  or  rigor  mortis.  As  stated,  certain  investi- 
gators have  suggested  that  the  formation  of  the  muscle 
clot  is  a  process  analogous  to  the  coagulation  of  blood, 
and  is  brought  about  by  ferment  action.  This  view 
is  not  yet  proven  and  must  at  present  be  considered  as 
only  hypothetical.  If,  however,  it  is  found  to  be  cor- 
rect, myosin  would  properly  be  classed  as  a  derived 
albuminoid,  its  progenitor  being  the  native  proteid. 

(2)  Heat.  The  effect  of  a  boiling  temperature 
upon  the  albumins  has  already  been  described.  They 
are  coagulated  into  a  mass  no  longer  soluble  in  water 
and  only  redissolved  by  treatment  which  changes  their 
chemical  constitution.  The  same  thing  happens  to 
nearly  all  the  globulins,  and  as  with  the  albumins, 
this   begins    at   varying  temperatures.      These   coagu- 


Protein  —  Mod  ifiecl   A  lb  u  minoids  65 

lated  bodies,  which  are  typified  by  the  white  of  an  egg 
after  contact  with  boiling  water,  are  materially  unlike 
the  original  compounds,  though  the  nature  of  the  modi- 
fication is  not  understood.  We  know  them  simply  as 
coagulated  albumins  and  globulins. 

(3)  Action  of  acids  and  alkalies.  When  albumins 
and  globulins  are  treated  with  dilute  mineral  acid,  such 
as  hydrochloric,  they  dissolve,  through  their  conversion, 
into  acid  albuminates.  The  action  of  dilute  alkalies  is 
similar,  only  that  alkali- albuminates  are  formed.  An- 
other effect  of  dilute  acids  upon  proteids  is  to  cause 
them  to  take  up  water,  or  suffer  hydrolysis.  These 
hydrolyzed  bodies  are  called  proteoses  as  a  general 
name.  This  term  signifies  that  they  are  derived  from 
proteids.  More  fully  specialized  names  are  albumose, 
from  albumin;  globulose,  from  globulin;  caseose,  from 
casein,  and  so  on.  The  important  property  w^hich  the 
proteoses  takes  on  is  their  greater  solubility  as  com- 
pared with  the  original  compounds.  This  change  has 
an  intimate  relation  to  digestive  processes,  or  to  the 
transference  of  the  insoluble  albuminoids  of  the  food 
into  the  blood  circulation,  because  in  the  stomach  the 
hydrochloric  acid  of  the  gastric  juice  plaj's  somewhat 
the  same  part  as  in  dilute  artificial  solutions  in  render- 
ing the  proteids  soluble. 

(4)  Ferments  of  digestion.  When  we  come  to  a 
discussion  of  the  processes  of  digestion  we  shall  learn 
that  nearly  every  digestive  fluid  contains  one  or  more 
ferments,  whose  ofSce  appears  to  be  to  cause  certain 
necessary  modifications  of  the  food  proteids,  The  gen* 
§VSi\  effect  of  these  ferm§Bt§  i§  tQ  JB^UCg  tbe§§  proteins 


66  The  Feeding  of  Animals 

to  take  up,  water,  which  transforms  them  to  proteoses, 
and  finally  to  peptones,  the  latter  being  so  soluble  as 
to  pass  through  the  walls  of  the  alimentary  canal  into 
the  blood.  These  proteoses  are  similar  to  those  formed 
by  the  action  of  dilute  acids,  and  in  digestion  may 
be  considered  as  products  intermediary  between  the 
original  food  proteids  and  the  peptones  which  are  the 
final  result  of  albuminoid  digestion.  The  acid  of  the 
stomach  and  the  alkaline  compounds  in  certain  intesti- 
nal juices  cooperate  in  bringing  about  these  necessary 
changes,  for  we  know  that  in  their  absence  the  digestive 
ferments  have  no  extensive  action  such  as  that  de- 
scribed. Proteoses,  i.  e.,  albumoses,  globuloses,  case- 
oses,  and  the  like,  are  soluble  in  water,  are  not  coagu- 
lated by  boiling  their  solutions,  and  in  other  ways  are 
unlike  the  proteids  from  which  they  are  derived.  They 
are  regarded,  however,  as  not  having  lost  their  albu- 
minoid character,  and,  as  will  be  shown  later,  they  are 
re-formed  by  the  metabolic  energy  of  the  animal  into 
bodies  similar  to  those  from  which  they  take  their  rise. 

(5)  Combinations.  There  are  many  nitrogenous 
compounds  found  in  plants  and  animals  which  it  is 
not  possible  to  classify  at  present  in  any  exact  manner. 
They  are  undoubtedly  derived  from  simple  proteids,  as 
those  to  which  reference  is  made  consist  of  albuminoids 
united  to  a  body  of  a  different  kind. 

There  are,  first  of  all,  certain  bodies  designated  as 
nucleo- albumins,  this  name  signifying  that  albumin  is 
united  to  a  nucleiii,  which,  in  its  turn,  is  a  combination 
of  an  albumin  with  phosphoric  acid.  The  best  known 
nucleo -albumin   in    agriculture   is   the  casein   of  milk. 


Protein  —  Modified  Albuminoids  67 

Some  of  the  properties  of  this  body  have  been  noticed 
in  discussing  the  action  of  ferments.  It  has  others 
which  it  is  well  to  mention.  In  the  first  place,  casein 
is  not  soluble  in  water.  It  is  not  in  solution  as  it  ex- 
ists in  milk,  but  is  regarded  as  being  in  a  swollen  con- 
dition. Again,  it  does  not  coagulate  when  milk  is 
boiled.  While  the  skin  which  forms  on  the  surface 
of  milk  at  a  boiling  temperature  contains  casein  as 
one  component,  the  only  genuine  coagulation  that  oc- 
curs is  of  the  albumin  present.  Every  housewife  has 
noticed  that  when  vinegar  is  added  to  milk  in  a  small 
quantity  the  milk  curdles.  This  is  because  the  casein 
is  modified  by  a  weakly  acid  medium.  A  generous 
quantity  of  common  salt,  or  of  certain  other  salts, 
would  have  a  similar  effect. 

The  nuclein,  which  forms  a  part  of  casein,  can  be 
split  into  an  albumin  and  phosphoric  acid,  and  is  an 
illustration  of  a  class  of  compounds  which  are  gen- 
erally distributed  in  plant  and  animal  tissue.  The  name 
is  suggestive  of  the  fact  that  these  bodies  exist  in  the 
nuclei  of  living  cells,  having  an  intimate  relation  to  the 
protoplasm.  Nucleins  are  also  found  in  milk  and  eggs, 
and  it  appears  quite  possible  that  they  take  a  pecu- 
liarly important  place  in  nutrition,  especially  with 
young  animals  and  milch  cows. 

Another  compound  widely  distributed  in  the  animal 
kingdom  is  mucin,  a  prominent  constituent  of  the 
slimy  secretions  of  the  mucous  membranes  that  line 
the  passages  of  the  animal  body,  such  as  the  throat 
and  the  intestines.  This  substance  appears  somewhat 
anomalous  in  being  a  combination  of  a  proteid  and  a 


68  The  Feeding  of  Animals 

carbohydrate  (animal  gum).  The  fact  of  such  a  union 
is  demonstrated  by  boiling  mucin  with  an  acid  when 
an  acid  albuminate  and  carbohydrate -like  body  are 
produced.  The  mucin-like  bodies  are  not  especially 
important  in  nutrition. 

The  blood  contains  a  modified  proteid  which  has  an 
importance  second  to  none  in  its  relation  to  the  nu- 
tritive processes.  Reference  is  made  to  hgemoglobin, 
which  arises  from  the  union  of  an  albumin  called 
globin  and  a  coloring  matter  (pigment)  called  haema- 
tin.  The  latter  is  peculiar  in  containing  iron.  The 
especial  function  of  hasmoglobin  is  as  a  carrier  of  oxy- 
gen, and  it  is  enabled  to  do  its  work  through  the 
property  of  taking  in  and  releasing  oxygen  with  great 
readiness.  This  action  will  be  discussed  later  when 
we  consider  respiration. 

The  gelatinoids. —  It  is  a  matter  of  common  obser- 
vation in  cookery  that  when  meat  containing  tendons 
(cartilage)  or  bones  is  submitted  to  the  action  of 
boiling  water  there  is  obtained  in  the  extract  a  sub- 
stance, which,  especially  when  it  is  cold,  we  recognize 
as  the  one  known  as  gelatine.  Gelatine  as  such  is  not 
found  in  the  animal  tissues,  but  is  derived  from  certain 
constituents  of  the  connective  tissues  like  the  collagen 
of  tendons  and  of  bones,  that  from  the  latter  source 
being  also  known  as  ossein.  Collagen  is  undoubt- 
edly transformed  into  gelatine  by  taking  up  water. 

Gelatine  is  insoluble  in  cold  water,  but  dissolves 
in  hot.  As  the  dry  commercial  article,  it  is  a  tena- 
cious substance  which,  when  prepared  in  thin  layers, 
j§  transparent.    When  collagen  is  ^cted  upon  b;^  taii- 


Protein  —  Non  -  Proteids  69 

nic  acid,  as  for  instance,  when  the  skin  of  an  animal 
is  treated  with  an  extract  of  hemlock  or  oak  bark,  the 
result  is  a  substance  which  does  not  putrefy,  and  which 
gives  to  a  tanned  hide  the  properties  of  leather. 

Keratin  and  similar  substances . —  The  hair,  wool, 
hoofs,  horns,  and  feathers  are  made  up  chiefly  of 
a  compaund  which  bears  the  name  keratin.  Chemi- 
cally, it  is  closely  related  to  the  true  proteids,  we  may 
believe,  because  when  treated  with  heat  or  with  chemi- 
cals like  acids  and  alkalies,  the  resulting  products  are 
nearly  similar  to  those  that  are  secured  in  the  same 
ways  from  albumins.  Sulphur  is  a  much  more  promi- 
nent constituent  of  keratin  than  of  the  native  pro- 
teids, the  analyses  of  human  hair  showing  as  high  as 
5  per  cent,  the  average  amount  found  in  horn  being 
3.30  per  cent.  These  keratin  bodies  belong  usually  to 
the  epidermis  or  outer  skin  of  the  animal,  and  are 
modifications  of  the  exterior  tissue  to  serve  certain 
distinct  purposes  where  rigidity  or  wearing  quality  is 
necessary. 

PROTEIN  —  THE  NON  -  PROTEIDS 

There  are  certain  nitrogen  compounds  included  in 
the  term  protein  which  are  non-proteid  in  character, 
that  is,  they  possess  physical  and  chemical  properties 
greatly  removed  from  those  which  characterize  albumin 
and  other  true  proteids.  Their  office  as  nutrients  is 
also  less  comprehensive  than  that  of  the  albuminoids. 

One  group  of  non -proteids  which  we  speak  of  under 
the   general   term  amides,   is   found   chiefly  in   plants. 


70  The  Feeding  of  Animals 

They  are  soluble  in  water,  and  consequently  are  diffu- 
sible throughout  the  plant  tissues.  It  is  believed  that 
they  are  the  forms  in  which  the  nitrogen  compounds 
of  the  plant  are  transferred  from  one  part  to  another, 
as,  for  instance,  from  the  stem  to  the  seed.  It  has 
generally  been  held  that  amides  are  more  abundant  in 
young  plants  than  in  mature.  A  larger  part  of  the 
nitrogen  of  roots  and  tubers  is  found  in  these  com- 
pounds than  in  other  feeding  stuffs,  the  proportion  in 
grains  being  the  least,  and  is  very  small  indeed.  Such 
investigations  as  have  been  conducted  point  to  the 
conclusion  that  amides  are  not  muscle -formers,  as  is 
the  case  with  proteids.  This  is  a  reason  for  regarding 
the  protein  of  coarse  foods,  roots,  and  tubq,rs,  as  of 
less  value  than  that  of  the  grains  and  grain  products. 

The  extractives  are  bodies  found  in  the  extract  ob- 
tained from  beef  with  cold  water.  After  the  albumin 
has  been  removed  from  such  an  extract  by  boiling, 
these  compounds  known  as  creatin  and  creatinin  chiefly 
constitute  the  nitrogenous  solids  that  remain.  Their 
food  value  is  small  if  anything,  for  they  appear  to 
pass  through  the  body  without  change. 


CHAPTER   VI 

THE  COMPOUNDS  OF  AXIMAL  XUTRITIOX,  COXCLUDED — 
THE  XITROGEX-FREE  COMPOUNDS 

Much  the  larger  proportion  of  dry  cattle  foods 
consists  of  non- nitrogenous  material.  This  is  espe- 
cially true  of  hays  and  cereal  grains,  consequently  we 
find  that  from  75  to  80  per  cent  of  the  dry  matter 
stored  in  a  farmer's  haymows  and  grain-bins  is  made 
up  of  substances  of  this  class.  While  these  com- 
pounds are  not  regarded  by  many  as  fundamentally  so 
important  as  the  nitrogenous,  in  quantity  the}'  un- 
questionably occupy  the  first  rank.  The  activities  of 
plant  life  are  largely  devoted  to  their  production,  and 
their  use  by  animal  life  is  correspondingly  extensive. 
They  may  properly  be  called  the  main  fuel  supply  of 
the  animal  world.  Other  nutrients  aid  in  maintaining 
muscular  force  and  animal  heat,  to  be  sure,  but  these 
compounds  are  the  principal  storehouse  of  that  sun- 
derived  energy  which  furnishes  the  motive  power  ex- 
hibited in  all  animal  life.  They  are  also  important 
building  materials,  for  they  fill  a  necessary  office  of 
this  kind  in  the  formation  of  milk  and  in  the  growth 
and  fattening  of  animals. 

The  compounds  of  this  class  contain  only  three  ele- 
ments,—  carbon,    hydrogen    and    oxygen.      They   may 

(71) 


72  The  Feeding  of  Animals 

be  derived,  therefore,  wholly  from  air  and  water,  and 
they  constitute  that  portion  of  our  cattle  foods  which 
is  drawn  from  never -failing  and  costless  sources  of 
supply. 

The  elementary  composition  of  typical  nitrogen - 
free  bodies  is  given  in  this  connection: 

Cellulose     Starch    Glucose    Saccharose    Stearin    Glean 

5^             *  ^               ^  i  1c 

Carbon 44.4  44.4  40.  42.1  76.7  77.4 

Hydrogen..     6.2  6.2  6.7  6.4  12.4  11.8 

Oxygen 49.4  49.4  53.3  51.5  11.  10.8 

The  non- nitrogenous  compounds  of  feeding  stuffs 
are  usually  divided  into  three  main  classes,  viz.;  crude 
fiber,  nitrogen -free  extract  and  fats  or  oils.  The  sec- 
ond class  is  sometimes  spoken  of  as  carbohydrates, 
because  it  includes  the  carbohydrates  as  its  principal 
members,  and  the  third  is  known  by  the  chemist  as 
ether -extract,  because  ether  is  used  to  extract  the  fats 
or  oils  from  the  vegetable  substances  in  which  they  are 
contained.  The  actual  fat  obtained  from  hay  and 
other  feeding  stuffs  is  always  less,  however,  than  the 
ether -extract. 

CRUDE    FIBER 

This  is  the  tough  or  woody  portion  of  plants.  It 
consists  largel}'  of  cellulose,  a  familiar  example  of 
which  in  a  nearly  pure  form  is  the  cotton  fiber  used 
in  making  cloth.  Crude  fiber  is  separated  from  asso- 
ciated compounds  by  the  successive  treatment  of  vege- 
table substance  with  weak  acids  and  alkalies,  and  as  so 
determined  is  sometimes  improperly  taken  to  represent 


Crude  Fiber  hi   the  Plant  73 

the  amount  of  cellulose  in  a  plant.  While  crude  fiber 
is  mainly  cellulose,  it  contains  a  small  proportion  of 
other  compounds,  and  besides,  more  or  less  cellulose 
is  dissolved  by  the  acid  and  alkali  treatment,  so  that 
the  percentages  of  crude  fiber  given  in  fodder  tables 
only  approximately  measure  the  cellulose  present  in 
feeding  stuffs. 

All  plant  tissue  is  made  up  of  cells,  the  walls  of 
which  are  chiefly  or  wholly  cellulose.  It  is  this  sub- 
stance out  of  which  is  built  the  framework  of  the  plant, 
and  which  gives  toughness  and  rigidity  to  certain  of 
its  parts.  The  more  of  this  a  feeding  stuff  contains, 
the  more  tenacious  it  is,  other  things  being  equal, 
and  the  more  difficult  of  mastication. 

The  proportion  of  crude  fiber  in  plants  varies  greatly 
with  the  species.  Large  plants  have  more  than  small 
ones,  as  a  rule.  The  dry  matter  in  the  trunks  and 
limbs  of  trees  is  mostly  wood}'  fiber,  and  the  chemical 
treatment  involved  in  making  paper  from  wood  has  for 
its  main  object  the  separation  of  this  from  other  sub- 
stances. Grass  and  other  small  herbage  plants  are  less 
rich  in  fiber,  still  less  existing  in  such  species  as  pota- 
toes, turnips  and  beets. 

The  proportions  of  cellulose  in  the  different  parts  of 
a  plant  are  greatly  unlike.  It  is  usually  most  abundant 
in  the  stem,  with  less  in  the  foliage  and  least  in  the 
fruit.  With  vegetables  like  potatoes  and  turnips,  the 
leaves  are  much  richer  in  fiber  than  the  tubers  or  roots, 
which  contain  a  comparativelj^  small  proportion.  Of  the 
grains  or  seeds  considerable  is  present  in  the  outer  coat- 
ings, while  but  little  is  found  in  the  interior.     Cousid- 


74  The  Feeding  of  Animals 

ering  feeding  stuffs  as  a  whole,  we  find  that  hays,  and 
especially  straws,  are  rich  in  crude  fiber,  while  tubers, 
roots  and  the  grains  contain  only  small  amounts.  In 
certain  by-product  grain  foods,  like  bran,  which  is  made 
up  mostly  of  the  seed -coatings,  fiber  is  present  in  fairly 
large  proportions,  while  in  other  materials  like  gluten 
meal,  which  are  derived  from  the  inner  parts  of  the 
grain,  the  percentages  are  very  small. 

The  stage  of  growth  at  which  a  plant  is  used  for 
fodder  purposes  has  a  marked  influence  upon  the  pro- 
portion of  crude  fiber.  In  young,  actively  growing  vege- 
table tissue,  the  cell -walls  are  thin,  but  as  the  plant  in- 
creases in  age,  these  thicken,  chiefly  through  the  depo- 
sition of  cellulose.  Pasture  grass  has  less  cellulose  than 
hay,  and  early  cut  grass  less  than  that  which  is  ripe. 
In  general,  the  toughness  and  hardness  of  mature  plants, 
as  compared  with  young,  is  due  to  the  increased  pro- 
portion of  woody  fiber,  although  the  decrease  in  the 
relative  amount  of  water  in  the  tissues  and  the  deposi- 
tion of  other  substances  have  more  or  less  effect. 

NITROGEN -FREE   EXTRACT 

This  name,  like  protein,  is  a  collective  term,  being 
used  to  designate  a  group  of  compounds  possessing 
certain  characteristics  in  common.  A  great  variety  of 
substances  are  included  under  this  head,  many  of  which 
are  among  the  most  familiar  objects  of  every -day  life. 
Here  we  find  the  starches,  sugars,  gums  and  vegetable 
acids,  compounds  universally  used,  and  which  even  chil- 
dren recognize  by  name.     Certain  of  these  non-nitrog- 


Nitrogen -free   Exirad — Carhohydrates  75 

enous  bodies  of  less  importance  are  not  so  "well  known, 
as,  for  instance,  such  uncommon  sugars  as  mannose 
and  galactose,  and  their  mother  substances,  mannan 
and  galactan. 

The  manufacture  of  beers  and  liquors  and  many  of 
the  ordinary  phenomena  of  cooking  operations,  are  based 
upon  the  chemical  properties  of  the  starches  and  sugars. 
To  the  presence  of  these  and  related  bodies  is  due  many 
of  the  agreeable  flavors  and  appetizing  characteristics  of 
certain  foods,  as,  for  instance,  the  sweetness  or  acidity 
of  fruits,  and  flavors  produced  in  grain  foods  under  the 
influence  of  heat. 

The  most  prominent  and  important  members  of  the 
nitrogen -free  extract  group  are  known  as  carbohy- 
drates, the  significance  of  this  term  being  that  these 
compounds  contain  carbon  united  with  hydrogen  and 
oxygen  in  the  proportions  in  which  these  two  elements 
exist  in  water. 

A  common  and  convenient  classification  of  the  car- 
bohydrates, though  not  strictly  rational  from  the  stand- 
point of  chemical  constitution,  is  the  following:  1.  The 
starches,  such  as  corn  and  potato  starch  and  those 
bodies  similar  in  elementary  composition,  including  cel- 
lulose, inulin,  glycogen,  the  dextrin s,  pectin  and  the 
gums.  2.  The  sugars,  of  which  there  are  two  main 
classes,  the  glucoses  and  the  sucroses,  the  main  sugar 
of  "corn  syrup"  being  a  familiar  example  of  the  former 
class,  and  the  ordinary  crystallized  sugar  of  commerce 
the  most  prominent  member  of  the  latter. 

The  starches. — Starch  is  a  widely  distributed  and 
abundant  constituent  of  vegetable  tissue.    Food  plants, 


76  The  Feeding  of  Animals 

especially  those  most  used  by  the  hunum  family,  con- 
tain it  in  generous  proportions,  in  some  seeds  as  much 
as  60  or  70  per  cent  being  present.  Probably  only  water 
and  cellulose  are  more  abundant  in  the  vegetable  world. 

Starch  does  not  exist  in  solution  in  the  sap,  but  is 
found  in  the  interior  of  plant  cells  in  the  form  of 
minute  grains,  which  have  a  shape,  size  and  structure 
characteristic  of  the  seed  in  which  they  are  found. 
Potato  starch  grains  are  large,  about  -3017  of  an  inch 
in  diameter,  and  are  kidney -shaped,  while  those  of  the 
wheat  are  smaller,  about  toVo  of  an  inch  in  diameter, 
and  resemble  in  outline  a  thick  burning-glass.  Corn- 
starch grains  are  angular,  being  somewhat  six-sided, 
and  those  of  other  seeds  show  marked  and  specific 
characteristics.  These  differences  in  size  and  shape 
furnish  the  most  important  means  of  detecting  adul- 
terations of  one  ground  grain  with  another,  as,  for 
instance,  when  corn  flour  is  mixed  with  wheat  flour,  a 
practice  not  unknown  at  the  present  time. 

Unless  modified  by  some  chemical  change,  starch  is 
not  dissolved  by  water.  The  starch  grains  are  not 
affected  by  cold  water,  and  in  hot  water  at  first  only 
swell  and  burst.  Prolonged  treatment  with  hot  water 
causes  chemical  changes  to  more  soluble  substances. 
For  this  reason  the  simple  leaching  of  a  fodder  mate- 
rial removes  no  starch;  at  least  not  until  fermentation 
occurs.  At  the  same  time  the  treatment  of  a  ground- 
grain  with  hot  water  so  breaks  up  the  starch  grains 
that  they  are  probably  acted  upon  more  promptly  by 
ferments  and  digestive  fluids,  though  perhaps  no  more 
fully,  than  when  uot  treated. 


Nitrogen- free    Extract  —  Starches  77 

It  is  somewhat  customary  to  refer  in  a  popular  way 
to  the  nitrogen -free  extract  of  feeding  stuffs  as  synony- 
mous with  starch  and  sugar.  Such  a  comparison  con- 
veys an  erroneous  impression.  The  nitrogen -free 
extracts  of  many  feeding  stuffs,  notably  the  straws 
and  hays,  contain  at  best  a  very  small  proportion  of 
these  carbohydrates,  the  amount  of  starch  often  being 
inappreciable.  It  is  doubtful  whether  these  coarse 
fodders  usually  contain  enough  to  be  chemically  de- 
termined. This  has  certainly  been  found  to  be  true 
in  some  cases.  On  the  other  hand,  the  dry  matter  of 
many  seeds,  such  as  rice  and  the  cereal  grains,  wheat, 
maize,  barley  or  oats,  is  largely  made  up  of  starch. 
The  same  is  true  of  potatoes  and  other  tubers.  John- 
son quotes  the  following  figures  from  Dragendorff: 

Amount  of  starch  in  plants 

Per  cent  Per  cent 

Wheat  kernel 68.5       Peas   39.2 

Eye  kernel 67.         Beans 39.6 

Oat  kernel 52.9       Flaxseed 28.4 

Barley  kernel 65.         Potato  tubers 62.5 

It  appears  that  in  grain  plants  starch  forms  most 
abundantly  during  the  later  development  of  the  seed. 
At  the  Maine  station  none  could  be  found  in  very  im- 
mature field  corn  cut  August  15,  while  on  September 
21  the  dry  matter  of  the  whole  plant  on  which  the  ker- 
nels had  matured  to  the  hardening  stage  contained 
15.4  per  cent.  In  general,  the  stem  and  leaves  of  for- 
age plants  are  poor  in  starch. 

The  distribution  of  starch  in  seeds  is  worthy  of 
note.    The  grain  of  wheat  has  been  carefully  studied 


78  The  Feeding  of  Animxds 

in  this  particular,  and  it  is  found  that  this  body  does 
not  normally  exist  in  the  seed -coatings,  this  tissue  con- 
sisting largely  of  mineral  matters,  proteids,  cellulose, 
and  gums.  On  the  contrary,  the  germ  and  the  interior 
material  deposited  around  it  are  rich  in  starch.  To  be 
sure,  wheat  bran,  which  is  now  very  largely  the  outer 
seed-coats  of  the  grain,  has  more  or  less,  but  this  is 
due  to  imperfect  milling.  It  is  very  evident,  there- 
fore, that  the  term  nitrogen -free  extract,  as  applied 
to  different  cattle  foods,  stands  for  greatly  unlike  mix- 
tures of  compounds,  for  we  have  largely  starch  in  the 
cereal  grains  and  mostly  other  substances  in  the  straws 
and  other  coarse  fodders.  The  importance  of  this  fact 
will  appear  in  considering  the  digestion  and  value  of 
food  compounds. 

Starch  is  an  important  commercial  article,  and  for 
this  purpose  is  mainly  obtained  from  corn  and  pota- 
toes. It  is  used  as  human  food,  as  a  source  of  dextrin 
and  in  other  ways.  By  treatment  with  an  acid,  corn- 
starch is  converted  into  the  glucose  of  our  markets. 

The  vegetable  gums. — It  has  become  evident,  doubt- 
less, during  our  discussion  of  nitrogen -free  extract, 
that  a  considerable  portion  of  this  class  of  compounds 
consists  of  something  else  than  the  carbohydrates  al- 
ready noticed.  For  example,  at  the  Maine  Experiment 
Station,  the  composition  of  several  samples  of  corn 
fodder  was  closely  investigated.  It  was  found  that 
the  proportions  of  starch  and  sugar  varied  greatly, 
mostly  in  accordance  with  the  stage  of  growth,  being 
much  more  abundant  in  the  mature  plant.  Even 
with  flint  corn   nearly  ripe,  not   over  one -half  of  the 


Nitrogen -free   Extract — Vegetable    Gums  79 

nitrogen -free  extract  of  the  entire  plant  was  fonnd  to 
be  starch  and  sugars.  The  other  half  evidently  con- 
sisted of  bodies  either  not  so  well  known  or  not  known 
at  all. 

Among  the  less  familiar  compounds  which  we  now 
recognize  as  existing  quite  abundantly  in  the  stem  and 
leaves  of  many,  if  not  all,  fodder  plants  are  the  vege- 
table gums,  some  of  which  are  designated  by  the 
chemist  as  pentosans.  Only  a  few  such  substances 
are  definitely  known,  one  of  which,  araban,  is  con- 
tained in  gum  arable,  gum  tragacanth,  cherry  gum, 
beet  pulp,  and  doubtless  in  various  other  materials; 
another  being  zylan  or  wood  gum,  which  may  be  sep- 
arated in  abundance  from  wood  and  straw.  Stone  has 
examined  a  large  number  of  agricultural  products  for 
these  gums,  and  if  present  methods  of  analysis  are 
accurate,  he  found  in  the  dr3'  matter  of  such  feeding 
stuffs  as  hays  from  several  species  of  grass,  corn  fod- 
der, sugar  beets,  rutabagas,  wheat -bran  and  middlings 
and  gluten  meal  from  6  to  over  16  per  cent,  the  high- 
est proportions  appearing  in  timothy  hay,  corn  fod- 
der, and  wheat -bran.  In  mature  field -corn  fodder 
he  obtained  about  16  per  cent,  thus  accounting  for 
about  half  of  the  nitrogen -free  extract  left  after  sub- 
tracting the  starch  and  sugars.  Wheat  bran  contained 
much  more  than  middlings,  and  the  least  was  present 
in  gluten  meal.  These  gums  are  surely  much  more 
abundant  in  the  coarse  foods  than  in  the  grains,  a 
fact  which,  as  we  shall  learn,  is  important  in  com- 
paring the  nutritive  value  of  different  classes  of  feed- 
ing stuffs. 


80  The  Feeding  of  Animals 

The  pectin  bodies.  —  Another  class  of  compounds 
much  like  the  gums,  and  perhaps  related  to  them 
chemically,  is  the  pectin  bodies.  Some  of  these  sub- 
stances are  gelatinous  in  appearance.  The  jellying  of 
fruits,  such  as  apples  and  currants,  is  made  possible  by 
their  presence.  They  exist  in  greater  abundance  in 
unripe  fruit  than  in  the  ripe,  consequently  the  former 
is  selected  for  jelly -making.  When  such  fruits  are 
cooked,  the  pectin  which  thej^  contain  takes  up  water 
chemically  and  is  transformed  into  a  gelatinous  sub- 
stance, and  the  secret  of  jelly-making  is  in  stopping 
the  cooking  process  before  the  chemical  transforma- 
tions have  passed  beyond  a  certain  point.  Mucilages 
not  greatly  unlike  the  gums  and  pectins  exist  in  cer- 
tain seeds  and  roots,  the  most  notable  instance  being 
flaxseed. 

The  sugars.  —  When  considered  from  the  stand- 
point of  efficiency,  the  sugars  are  the  most  valuable 
of  all  the  carbohydrates,  although  in  quantity  they  are 
much  less  important  than  the  starches,  because  they 
are  found  only  in  small  amounts  in  the  hays  and  to  a 
scarcely  appreciable  extent  in  the  grains.  Certain  dis- 
tinctively sugar  plants,  to  be  mentioned  later,  are 
grown  agriculturally,  which  are  sometimes  used  as 
cattle  foods. 

Unlike  starch,  the  sugars  are  found  in  solution  in 
the  sap  of  growing  plants.  It  is  probable  that  these 
are  the  forms  in  which  carbohydrate  material  is  trans- 
ferred from  one  part  of  the  plant  to  another.  It  is 
easy  to  see  that  some  such  medium  of  exchange  is 
necessary.     The  actual  productioji  of  new  vegetable 


I 


Nitrogen- free   Extract  —  Sugars  81 

substance  takes  place  in  the  leaves.  When,  therefore, 
cell -walls  and  starch -grains  are  to  be  constructed,  in 
the  stem  and  frnit,  the  building  material  must  be  car- 
ried from  the  leaves  to  these  parts  in  forms  which  will 
readily  pass  through  intervening  membranes.  Except- 
ing certain  soluble  compounds,  closely  related  to  starch, 
the  sugars  appear  to  be  the  only  available  bodies  fitted 
for  this  office. 

It  is  very  seldom  that  a  plant  contains  only  a  single 
sugar.  Generally  two  or  more  sugars  are  found  to- 
gether. This  is  especially  the  case  in  the  corn  plant, 
sorghum  and  the  juicy  fruits,  and  the  proportions  of 
each  depend  somewhat  upon  the  stage  of  growth  of 
the  plant. 

The  most  important  sugar,  commercially  considered, 
is  saccharose,  which  is  the  ordinary  crystallized  product 
of  the  markets.  As  a  human  food  it  is  widely  used,  and 
is  especially  valuable ;  and  its  manufacture  and  sale  con- 
stitute a  prominent  industry.  This  sugar  is  obtained 
mostly  from  two  plants,  sugar  cane  and  the  sugar  beet. 
It  also  exists  abundantly  in  sorghum  and  in  considerable 
proportions  in  ordinary  field  corn.  The  first  spring  flow 
of  sap  in  one  species  of  maple  tree  is  richly  charged 
with  it,  and  in  a  few  states  large  quantities  of  maple 
sjTup  and  sugar  are  manufactured. 

Saccharose  is  not  a  prominent  constituent  of  the 
more  common  cattle  foods.  While  it  occurs  in  meadow 
grasses,  in  sweet  potatoes  and  in  roots,  and  perhaps  in 
minute  proportions  in  certain  seeds,  it  is  only  when  the 
fresh  corn  plant,  sorghum  and  sugar  beets  are  fed  that 
it  constitutes  a  material    part  of   the  ration.     In  corn 


82  The  Feeding  of  Animals 

stover  and  in  silage  there  is  practically  none,  it  having 
been  destroyed  by  the  fermentations  that  have  taken 
place. 

The  fruits  generally  contain  saccharose,  mixed  with 
other  sugars  and  organic  acids,  and  upon  the  relative 
proportions  of  these  compounds  depends  the  character 
of  the  fruit  as  to  acidity  or  sweetness. 

A  sugar  that  is  intimately  related  to  the  first  growth 
which  occurs  in  the  germination  of  seeds  is  maltose, 
for  it  stands  as  an  intermediate  product  between  the 
store  of  starch  in  the  seed  and  the  new  tissues  of  the 
sprout.  The  solution  that  the  brewer  extracts  from 
the  malted  grains  contains  this  compound  as  the  prin- 
cipal ingredient,  and  through  succeeding  fermentations 
in  the  beer  vats  it  is  broken  up  into  alcohol  and  other 
compounds.  It  sustains  an  important  relation,  there- 
fore, to  the  production  of  beers  and  other  alcoholic 
liquors.  The  glucose  syrups  found  in  the  markets  some- 
times contain  small  quantities  of  this  sugar.  It  is  also 
found  abundantly  in  the  intestinal  canal  during  the  di- 
gestion of  food,  being  derived  from  starch  and  other  car- 
bohydrates. Maltose  is  similar  to  cane  sugar  in  ultimate 
composition  but  not  in  constitution,  though  as  a  nutrient 
it  evidently  has  an  equivalent  value.  So  far  as  known, 
however,  it  does  not  appear  to  occur  in  material  quan- 
tities in  feeding  stuffs. 

Another  important  sugar  is  dextrose  or  grape  sugar, 
or  what  is  known  in  the  markets  as  glucose.  Excepting 
in  the  hands  of  the  chemist  it  is  seldom  seen  as  crystals, 
although  these  appear  in  the  "candying"  of  honey  and 
of  raisins.     Its  commercial  forms  are  molasses  and  the 


Nitrogen- free   Extract — Acids  83 

syrups.  Dextrose  is  found  iu  practically  the  same  plants 
that  contain  saccharose,  such  as  sorghum,  maize  and  the 
fruits.  So  far  as  known,  it  is  always  associated  with 
some  other  sugar.  On  account  of  its  difficult  crystalli- 
zation and  a  lower  degree  of  sweetness,  it  is  less  valuable 
for  commercial  purposes  than  cane  sugar.  That  which 
appears  in  the  market  is  largely  made  from  starch  by  the 
use  of  an  acid,  and  it  is  often  utilized  in  adulterating 
the  more  costly  saccharose.  Many  seem  to  regard  glu- 
cose as  a  substance  deleterious  to  health,  but  in  consid- 
eration of  the  fact  that  in  digestion,  starch  and  most 
other  sugars  are  reduced  to  this  compound  before  en- 
tering the  circulation  of  the  animal,  this  view  does  not 
seem  to  be  sustained.  In  fact,  there  is  a  lack  of  evi- 
dence to  show  the  ill  eifect  of  glucose  either  upon  man 
or  animals. 

Still  another  sugar  is  Jevulose  or  fruit  sugar,  the 
composition  of  which  is  identical  with  dextrose  but  which 
has  a  diiferent  chemical  constitution.  It  accompanies 
dextrose  and  is  found  in  some  fruits  in  considerable 
quantities.  It  is  as  sweet  as  cane  sugar,  but  does  not 
form  crystals  with  the  same  readiness. 

The  acids. — Other  substances  besides  those  of  a  car- 
bohydrate character  are  included  in  the  nitrogen -free 
extract.  Chief  among  these  are  the  organic  acids,  com- 
pounds which  are  found  mostly  in  the  fruits,  although 
they  appear  in  certain  fermented  products,  such  as  silage 
and  sour  milk.  The  most  important  and  well-known  of 
these  are  acetic  acid,  found  in  silage  and  vinegar,  citric 
acid  in  lemons,  lactic  acid  in  sour  milk  and  silage,  malic 
acid  in  many  fruits,  such  as  currants  and  apples,  and 


84  The  Feeding  of  Animals 

oxalic  acid  in  rhubarb.  Sometimes  these  acids  are  free, 
that  is,  not  combined  with  any  other  compound,  and 
sometimes  they  are  united  with  lime  or  some  other  base, 
forming  a  salt.  Excepting  the  fruits,  only  fermented 
feeding  stuffs  contain  acids  to  an  appreciable  extent. 
When  milk  sours,  the  sugar  in  it  is  changed  to  lactic  acid 
under  the  influence  of  a  ferment.  In  silage,  various 
acids  develop,  the  main  one  being  lactic,  accompanied 
by  acetic  and  other  acids  in  much  smaller  proportions. 
These  are  formed  chiefly  at  the  expense  of  the  sugars 
that  enter  the  silo  in  the  corn  or  other  material  which 
is  subjected  to  fermentation. 

ANIMAL   CARBOHYDRATES 

A  study  of  the  composition  of  the  animal  body 
teaches  us  that,  unlike  plants,  it  is  very  poor  in  carbo- 
hydrate compounds.  Only  two  carbohydrates  are  of 
distinctively  animal  origin,  viz;  glycogen  or  animal 
starch,  and  milk  sugar. 

Glycogen  is  closely  related  to  starch,  having  the  same 
percentage  composition.  It  is  a  white  powder,  soluble 
in  water,  and  may  be  extracted  in  very  small  amounts 
from  the  muscles  and  liver,  the  latter  being  the  place 
where  it  is  produced.  As  we  shall  see  later,  it  seems  to 
perform  a  very  important  office  in  nourishing  the  animal 
body.  It  was  formerh^  believed  that  another  carbohy- 
drate exists  in  muscle  called  inosite,  but  it  is  now  known 
that  this  substance  belongs  to  a  different  class  of  com- 
pounds. 

The  only  sugar  of  animal  origin  which  is  abundant 


i 


Nitrogen -free   Extract  —  Carbohydrates  85 

in  farm  life  is  that  found  in  milk  and  which  is  known 
in  commerce  as  milk  sugar  or  lactose.  The  milk  of  all 
mammals  contains  sugar,  which  appears  to  be  the  same 
compound  with  every  species  so  far  investigated.  When 
fed  wholly  from  the  mother,  this  is  the  only  carbohydrate 
which  young  mammals  receive  in  their  food.  The  aver- 
age proportion  of  sugar  in  the  milk  of  domestic  animals 
varies  from  three  to  six  parts  in  a  hundred,  cow's  milk 
containing  about  five  parts.  When  the  cream  is  removed 
much  the  larger  part  of  sugar  remains  in  the  skimmed 
milk,  and  in  cheese-making  it  is  nearly  all  found  in  the 
whej',  from  which  the  milk  sugar  of  commerce  is  ob- 
tained. Very  soon  after  milk  is  drawn,  unless  it  is 
heated  to  the  point  of  sterilization,  or  is  treated  with 
some  antiseptic,  the  lactose  begins  to  diminish  in  quan- 
tity, being  converted  into  lactic  acid  through  the  action 
of  germ  life.  Sour  milk,  therefore,  is  different  from 
sweet  in  at  least  one  compound,  and  this  change  causes 
at  least  a  slight  modification  of  food  value. 


CHEMICAL   RELATIONS   AND   CHARACTERISTICS    OF 
THE    CARBOHYDRATES 

The  various  carbohydrates,  which  have  been  pre- 
viously described,  are  greatly  unlike  in  appearance, 
taste  and  other  physical  qualities,  but  they  are  closely 
related  chemically.  This  is  shown  not  only  by  what 
the  chemist  knows  of  their  constitution,  but  also  by 
the  readiness  with  which  one  passes  into  another, 
for  example,  the  transformation  of  starch  into  dex- 
trose.    Under  the  influence  of  certain  agencies,  such  as 


86  The  Feeding  of  Animals 

heat,  ferments  and  hot  acids,  certain  carbohydrates  may 
be  changed  to  other  bodies  of  the  same  class.  This 
fact  is  important  in  the  arts,  and  no  less  so  in  plant 
and  animal  nutrition.  The  movements  of  these  com- 
pounds in  plants  and  their  uses  as  nutrients  depend 
largely  upon  these  transformations,  as  do  also  certain 
phenomena  in  cooker^^ 

Heat  is  one  immediate  cause  of  some  of  these 
changes.  Starch,  when  heated,  becomes  dextrine,  a 
water-soluble,  gum -like  substance.  This  occurs  in 
baking  corn  and  wheat  bread;  so  it  does  in  toasting 
bread,  and  the  bread -crust  tea  of  the  sickroom  is  in 
part  a  solution  of  dextrine.  Probably  this  substance 
is  digested  with  greater  ease  than  starch,  because  it  is 
an  intermediate  stage  between  starch  and  glucose,  the 
latter  being  the  final  product. 

Hot,  dilute  acids,  even  the  vegetable  acids,  such  as 
those  found  in  vinegar  and  in  fruits,  transform  starch, 
dextrin,  gums  and  pectin  bodies  into  various  sugars,  of 
which  dextrose  is  the  principal  one.  Saccharose  is 
changed  to  dextrose  and  levulose  in  the  same  way. 
These  chemical  facts  find  an  application  in  the  manu- 
facture of  glucose  from  cheaper  materials,  and  in  cook- 
er}'  where  vinegar  and  acid  fruits  are  used. 

These  transformations  are  also  brought  about  by 
the  influence  of  bodies  called  ferments.  For  instance, 
the  carbohydrates  in  a  grain  of  barley  are  largely  not 
available  for  nourishing  the  new  growth  that  takes 
place  during  germination,  because,  being  mostly  insolu- 
ble, they  cannot  be  transferred  from  the  seed  to  the 
point  where  new  tissue  is  formed.     It  is  so  arranged 


Nitrogen- free    Extract — Carbohydrates  87 

that  a  ferment  present  in  the  seed,  called  diastase, 
acts  upon  the  starch  and  converts  it  into  maltose,  a 
sugar.  The  brewer  takes  advantage  of  this  fact  when 
he  malts  or  germinates  barley,  this  being  nothing  more 
than  the  same  change  of  starch  into  sugar,  which  oc- 
curs during  germination  in  the  ground.  This  maltose 
is  utilized  by  the  young  plant  to  form  new  tissue  and 
by  the  brewer  as  a  source  of  alcohol.  In  the  animal 
body,  especially  in  the  mouth  and  intestines,  are  found 
ferments  which  accomplish  essentially  the  same  result. 
Through  their  diastatic  influence  the  starch,  dextrose, 
cane  sugar  and  other  carbohydrates  are  transformed, 
probably  by  successive  stages,  finally  into  glucose  (dex- 
trose mainly)  in  which  form  the  carbohydrate  nutri- 
ents enter  the  blood. 

The  chemical  changes  so  far  noted  are  all  in  one 
direction,  i.  e.,  the  taking  up  of  the  elements  of  water 
to  form  new  compounds,  as,  for  instance,  the  trans- 
formation of  starch  to  dextrose  or  cane  sugar  into  in- 
vert sugar. 

Up  to  the  present  time,  however,  no  chemist  has 
discovered  a  way  of  reversing  this  process,  and  by  ab- 
stracting the  elements  of  water  from  the  glucoses  pro- 
ducing cellulose,  starch  and  cane  sugar.  That  the  plant 
can  do  this,  however,  is  certainly  true.  Cell  walls  and 
starch  grains  are  undoubtedly  made  from  the  sugars 
under  the  influerice  of  what  we  blindly  call  vital  force. 

The  carbohydrates,  especially  the  sugars,  possess 
such  chemical  properties  as  cause  them  to  be  easily  de- 
stroyed and  lost  from  the  feeding  stuff  in  which  they 
are  contained.     If  grass  or  corn  fodder  is  allowed  to  lie 


88  The  Feeding  of  Animals 

in  a  mass  in  a  green  or  wet  condition,  there  is  very 
material  loss  of  dry  matter,  due  to  the  breaking  up  of 
the  sugars  and  other  carbohydrates  into  new  compounds 
under  the  influence  of  ferments.  This  action  occurs  in 
the  silo,  where  the  sugars  are  used  to  form  considerable 
quantities  of  acids  besides  water  and  carbon  dioxid. 
Loss  from  this  cause  often  occurs  in  the  grain  bin, 
where  new  grain  not  sufficiently  dry  is  stored.  The 
sugars  in  canned  vegetables  or  fruits  that  are  not  prop- 
erly heated  or  sealed  soon  disappear,  either  to  be  lost 
in  gaseous  products  or  to  be  converted  into  compounds 
of  an  entirely  different  character.  All  such  fermeuta- 
tions  result  in  a  diminished  food  value.  Not  only  is 
there  an  actual  disappearance  of  dry  matter  from  the 
affected  material,  but  this  is  brought  about  at  the  ex- 
pense of  some  of  the  most  valuable  food  compounds. 
For  this  reason  the  farmer  should  exercise  great  care 
in  the  storage  and  preservation  of  his  cattle  foods.  The 
dangers  of  loss  from  these  fermentations  are  greater 
than  is  generally  appreciated,  for  the  chemist  finds  that 
in  drying  green  or  wet  foods  under  conditions  more 
favorable  than  often  pertain  to  farm  practice  he  is  un- 
able to  avoid  it  to  a  greater  or  less  extent. 

FATS    OR    OILS 

When  any  finely- ground  feeding  stuff,  either  straw 
or  hay,  is  submitted  to  the  leaching  action  of  ether, 
chloroform,  or  certain  other  liquids,  several  compounds 
are  taken  into  solution,  the  main  and  important  ones 
being  fats  or  oils.      These  bodies   make  up  the  chief 


Fats   or    Oils  89 

portion  of  such  an  extract  from  seeds,  while  material 
so  derived  from  hay,  straw  and  other  coarse  fodders 
also  contains  a  considerable  amount  of  wax,  chlorophyll 
and  other  substances.  Tables  that  show  the  compo- 
sition of  feeding  stuffs  have  a  column  which  is  some- 
times designated  "ether -extract,"  and  sometimes  "tats 
or  oils."  The  former  is  the  more  accurate  term,  be- 
cause the  compounds  which  it  is  the  intention  to  de- 
scribe are  often  no  more  than  half  fats  or  oils.  The 
real  value  of  the  "ether -extract "  from  different  feed- 
ing stuffs  is  partly  determined,  therefore,  by  its  source. 
When  it  is  all  oil,  or  nearlj'  so,  it  is  worth  much  more 
for  use  by  the  animal  than  when  it  is  made  up  to  quite 
an  extent  of  other  bodies. 

The  proportions  of  fat  or  oil  in  feeding  stuffs  var}' 
within  wide  limits.  In  general,  seeds  and  their  by- 
products contain  more  than  the  coarse  foods,  the  differ- 
ences in  the  percentages  of  actual  oil  being  greater 
than  is  indicated  by  the  ether- extract.  Straws  natu- 
rally have  less  oil  than  the  hays.  But  little  is  found 
in  the  dry  matter  of  roots  and  tubers.  Among  the 
cereal  grains  and  other  more  common  farm  seeds,  corn 
and  oats  show  the  largest  amounts,  the  proportion  in 
dry  matter  being  from  five  to  six  in  one  hundred,  while 
wheat,  barley,  vyQ,  peas,  and  rice  contain  much  smaller 
percentages,  wheat  having  about  2  per  cent,  and  rice 
sometimes  not  over  one -fifth  of  1  per  cent.  Agri- 
cultural seeds  that  are  especially  oleaginous  are  cotton- 
seed, flaxseed,  sunflower  seeds,  and  the  seeds  of  manj- 
species  belonging  to  the  mustard  family,  such  as  rape. 
Peanuts,  cocoanuts  and  palm  nuts  are  also  very  rich  in 


90  The  Feeding  of  Animals 

oil.     The  average  percentages  in  these  seeds  and  nuts 
are  approximately  as  given  below: 

Oil  in  certain  seeds 

Per  cent  Per  cent 

Linseed 34       Peanuts 46 

Cottonseed 30       Cocoanuts G7 

Sunflower  seed 32       Palm  nuts 49 

Rape  seed 42      Poppy  seed 41 

Mustard  seed 32 

The  oils  from  all  the  above  are  important  commer- 
cial products,  being  used  in  a  great  variety  of  ways 
m  human  foods  and  in  the  arts.  In  many  cases,  the 
refuse  from  this  extraction  goes  back  to  the  farm  as 
food  for  the  cattle.  This  is  especially  true  of  linseed 
and  cottonseed. 

The  vegetable  and  animal  fats  and  oils  ma}',  for 
convenience'  sake,  be  discussed  in  two  divisions,  the 
neutral  fats  or  glycerides  and  the  fatty  acids.  The  neutral 
fats  are  combinations  of  the  fatty  acids  with  glj^cerine. 
When,  for  instance,  lard  is  treated  at  a  high  tempera- 
ture "with  the  alkalies,  potash  and  soda,  glycerine  is 
set  free  and  an  alkali  takes  its  place  in  a  union  with 
the  fatty  acids.  This  is  the  chemical  change  which 
occurs  in  soap -making.  There  are  several  of  these  neu- 
tral fats,  the  ones  most  prominent  and  important  in 
agriculture  being  those  abundant  in  butter  and  in  the 
body  fats  of  animals;  viz.,  butyrin,  caproin,  caprylin, 
caprin,  laurin,  myristin,  olein,  palmatin,  and  stearin. 
Butyrin  is  a  combination  of  butyric  acid  and  glycer- 
ine, stearin  of  stearic  acid  and  glycerine,  and  so  on. 

These  individual  fats  possess  greatly  unlike  physical 


Fats  or   Oils  91 

properties.  At  the  ordinary  temperature  of  a  room 
some  are  liquid  and  some  are  solid,  olein  belonging  to 
the  former  class  and  palmatin  and  stearin  to  the  latter. 
It  is  a  matter  of  common  observation  that  butter,  lard 
and  tallow  differ  in  hardness  at  a  given  temperature, 
and  by  the  use  of  a  thermometer  it  may  easily  be  dis- 
covered that  their  melting  points  are  not  the  same.  As 
these  animal  fats  are  in  all  cases  chiefly  mixtures  of 
olein,  palmatin,  and  stearin,  stearin  being  a  solid  at 
ordinary  temperatures,  and  olein  a  liquid  at  anything 
above  the  freezing  point,  it  is  evident  that  the  relative 
proportions  of  these  compounds  will  affect  the  ease  of 
melting  and  the  hardness  of  the  mixtures  of  which  they 
are  a  part.  Tallow  having  more  stearin  than  lard  and 
butter  and  less  olein,  is  consequently  much  more  solid 
on  a  hot  day. 

Milk  fat  contains  not  only  the  three  principal  fats 
but  also  the  others  mentioned,  butyrin,  caproin,  caprylin, 
caprin,  laurin  and  myristin,  in  small  proportions,  and 
these  latter  tend  to  give  butter  certain  properties  that 
distinguish  it  from  the  other  animal  fats,  which  are 
almost  wholly  palmatin,  olein  and  stearin.  Doubtless 
the  flavor,  texture  and  resistance  of  butter  to  the  effects 
of  heat  are  much  influenced  by  the  proportions  of  the 
numerous  fats  it  contains,  but  there  is  much  connected 
with  this  subject  of  which  we  are  still  ignorant. 

Free,  fatty  acids  exist  in  nature.  They  are  not  found 
in  butter,  lard  and  tallow  unless  these  substances  have 
undergone  fermentations,  or,  as  we  say,  have  become 
rancid.  The  characteristic  flavor  of  strong  butter  is  due 
to  free  butyric  acid,  which,  because  of   fermentations, 


92  The  Feeding  of  Animals 

has  parted  from  the  glycerine  with  which  it  was  origi- 
nally combined  in  the  milk.  In  plant  oils,  on  the  other 
hand,  are  found  considerable  proportions  of  the  free 
fatty  acids,  some  of  which  have  not  been  discovered  so 
far  in  animal  fats,  either  free  or  uncombined. 

Perhaps  no  one  has  studied  plant  oils  more  thor- 
oughly than  Stellwaag,  who  investigated  the  ingredients 
of  the  ether  and  benzine  extracts  from  plants.  His 
results  show  that  not  only  do  these  extracts  include 
substances  which  are  not  fats,  but  that  a  considerable 
proportion  of  free  fatty  acids  is  always  present,  some- 
times in  quantities  exceeding  the  neutral  fats: 

Composition  of  ether- extracts  {per  cent) 

Neutral        Free  fatty        Mateiial  not 
fats  acids  saponifiable 

Hay 23.7  37.3  30.8 

Malt  sprouts   24.7  30.1  34.5 

Potatoes 16.3  56.9  10.9 

Beets 23.  35.3  10.7. 

Maize,  kernel 88.7  6.7  3.7 

Barley , 73.  14.  6.1 

Oats 61.6  27.6  2.4 

It  appears,  as  before  stated,  that  ether- extract,  es- 
pecially that  from  coarse  fodders,  may  consist,  to  a  large 
extent,  of  materials  which  should  not  be  classed  among 
the  fats.  Stellwaag  demonstrated  that  only  about  60 
per  cent  of  the  hay  extract  which  he  investigated  con- 
sisted of  oil.  On  the  contrary,  the  extracts  from  the 
grains  proved  to  be  nearly  all  oil.  Moreover,  the  grain 
oils  were  made  up  principally  of  glycerides,  and  those 
from  hay,  malt  sprouts,  potatoes  and  beets  consisted 
largely  of  free  fatty  acids. 


CHAPTER   VII 

THE  COMPOSITION  OF  THE  BODIES   OF  FARM  ANIMALS 

The  principal  compounds  existing  in  the  bodies  of 
our  farm  animals  have  been  quite  fully  considered  on 
preceding  pages.  It  now  remains  for  us  to  learn  some- 
thing of  the  proportions  of  these  substances  that  are 
needed  in  constructing  the  carcasses  and  other  tissues 
of  steers,  sheep  and  swine;  for  it  is  about  these  spe- 
cies that  we  have  the  most  extensive  and  accurate 
knowledge  as  related  to  chemical  composition.  Cer- 
tainly such  knowledge  is  important.  The  animal  is 
the  direct  product  of  food,  and  before  we  can  consider 
intelligent!}'  the  functions  of  food  nutrients  and  the 
ways  in  which  they  are  made  to  fulfil  their  offices,  we 
must  understand  what  is  to  be  done.  So  far,  then,  as 
it  is  a  matter  of  construction,  what  must  be  accom- 
plished by  the  use  of  food  in  building  the  body  of  an 
animal  ?  It  has  doubtless  become  evident  from  fore- 
going statements  that  many  compounds  are  common 
to  the  vegetable  and  the  animal  kingdoms.  The  chem- 
ical constituents  in  plants  and  animals  are  classified  in 
the  same  way,  also;  viz.,  water,  ash,  or  mineral  com- 
pounds, protein,  carbohydrates,  and  fats.  Here  the 
similarity  stops,  for  the  proportions  of  these  classes 
as  found  in  the  fat  steer  and  in  the  stalk  of  maize  are 

(93) 


94  The  Feeding  of  Animals 

entirely  unlike,  and  what  is  true  in  this  respect  of  the 
steer  and  the  maize  is  true  of  all  other  animals  and 
plants.  The  dry  matter  of  the  vegetable  world  con- 
sists most  largely  of  fiber,  starch  and  other  carbohy- 
drates, while  animal  tissues  contain  these  compounds 
in  so  small  a  proportion  as  to  be  inappreciable  in  stat- 
ing the  percentage  composition.  In  the  average  animal 
dry  matter,  as  it  appears  in  the  market,  the  fats  are 
the  leading  constituents,  and  the  proportion  of  protein 
is  more  than  twice,  perhaps  three  times,  that  in  average 
vegetable  tissue. 

In  considering  the  composition  of  farm  animals, 
.we  may  first  divide  the  body  substances  into  water  and 
dry  matter.  The  dry  matter,  aside  from  the  contents 
of  the  stomach  and  intestines,  and  the  food  ingredients 
in  the  way  to  being  used,  essentially  belongs  to  three 
classes  of  compounds,  ash,  protein,  and  fats,  which,  as 
is  the  case  with  water,  are  present  in  greatly  varying 
proportions  in  different  species,  and  even  in  the  same 
species  according  as  the  animal  is  j^oung  or  old,  lean  or 
fat.  Our  knowledge  on  this  subject  is  largely  derived 
from  the  investigations  of  Lawes  and  Gilbert,  at  Roth- 
amsted,  England.  These  investigators  carried  through 
the  great  effort  of  analyzing  the  entire  bodies  of  ten 
animals  representing  two  species  at  different  ages,  and 
three  species  in  different  conditions  of  fatness.  At  the 
Maine  Experiment  Station  in  this  country,  the  bodies' 
of  four  steers  were  analyzed,  exclusive  of  the  skin,  two 
steers  being  younger  and  not  so  fat  as  the  other  two. 
From  these  data  a  very  fair  knowledge  may  be  obtained 
not  only  of  the  composition  of   the  bodies  of  bovines 


i 


Composition  of  Farm  Animals  95 

sheep,  and  swine,  but  also  of  the  extent  to  which  this 
composition  is  affected  by  ao^e  and  condition: 

Composition  of  farm  animals  (per  cent) 

Species  Water  Ash  Protein  Fat 

Ox,  well-fed 66.2  5.9  19.2  8.7 

Ox,  half-fat 59.  5.2  18.3  17.5 

Ox,  fat 49.5  4.4  15.6  30.5 

Sheep,  lean 67.5  4.  18.3  10.2 

Sheep,  well-fed 63.2  3.9  17.4  15.5 

Sheep,  half- fat 58.9  3.8  16.  21.3 

Sheep,  fat 50.9  3.3  13.9  31.9 

Sheep,  very  fat 43.3  3.1  12.2  41.4 

Swine,  well-fed 57.9  2.9  15.  24.2 

Swine,  fat 43.9  1.9  11.9  42.3 

Fat  calf 64.6  4.8  16.5  14.1 

Steer,  17-months 59.4  4.4  17.4  18.8 

Steer,  17 -months 57.1  5.2  17.5  20.2 

Steer,  24 -months  53.1  5.1  16.6  25.2 

Steer,  24 -months 53.4  5.2  16.8  24.6 

It  is  always  more  or  less  surjirising  to  the  learner 
to  ascertain  that  the  bodies  of  farm  animals  of  vari- 
ous species  and  in  various  conditions  are  about  half 
water.  This  is  water  that  is  not  in  any  way  chemically 
united  with  associated  compounds,  but  exists  in  the 
blood  and  tissues  in  a  free  state,  and  may  be  dried  out 
in  the  usual  manner.  Next  to  water,  fat  is  the  most 
abundant  material,  protein  and  ash  following  in  the 
order  named. 

Perhaps  the  most  striking  fact  displayed  is  the  great 
variation  in  the  proportion  of  these  ingredients  accord- 
ing to  the  age  and  condition  of  the  animal.  For  in- 
stance, the  percentage  of  water  in  the  fat  calf  is  much 


96  The  Feeding  of  Animals 

greater  than  in  the  fat  ox,  and  this  is  an  illustration 
of  a  general  truth,  that  mature  animals  are  less  watery 
than  young  ones.  The  amount  of  water  present  in  the 
animal  body  is  also  influenced  to  a  marked  extent  by 
the  degree  of  fatness.  The  half -fat  ox  contained  over 
8  per  cent  more  water  than  the  fat,  the  store  sheep  22 
per  cent  more  than  the  extra  fat,  and  the  store  pig  14 
per  cent  more  than  the  fat.  The  explanation  of  this, 
as  before  stated,  is  not  that  fat  replaces  water  already 
in  the  tissues  of  the  lean  animal,  but  that  the  increase 
is  much  more  largely  dry  matter  than  was  the  original 
body  substance.  It  is  obviously  true,  also,  that  in  fat- 
tening an  ox  or  sheep,  thus  increasing  the  relative 
amount  of  fat,  the  proportions  in  the  dry  substance  of 
ash  and  protein  are  decreased.  The  above  statements 
are  explained  by  the  results  obtained  by  Lawes  and 
Gilbert  in  determining  the  composition  of  the  increase 
while  animals  are  fattening: 

Water      Ash        Protein         Fat 

ic  i             i  i 

Lean  ox 662  5.9  19.2  87 

Lean  sheep 67.5  4.  18.3  10.2 

Well-fed  swine 57  9  2.9  15.  24.2 

Average  of  lean  animals   ...     63.9       4.3         17.5         14.3 
Av.  of  increase  while  fattening     23.8       1.1  7.3         67.8 

This  comparison  of  the  composition  of  lean  animals 
and  of  the  increase  when  they  are  fattened  is  a  sufficient 
explanation  of  the  less  watery  and  fatter  condition  of 
the  animal  when  ready  for  the  market.  The  store 
animal  is  nearly  two -thirds  water  and  about  one -sev- 
enth fat,   while  the  increase  is  less  than   one -quarter 


1 


Composition  of  Farm  Animals  97 

water  and  over  two -thirds  fat.  The  percentage  of  pro- 
tein in  the  increase  is  also  very  small. 

Not  only  does  fattening  an  animal  materially  modifj^ 
the  composition,  bnt  the  proportion  of  butcher's  meat 
is  greatly  increased- 

Proportion  of  dressed  carcass  {per  cent) 

Ox  Sheep  Swine 

Lean  animal 47.  45.  73. 

Fat  animal 60.  53.  82. 

These  slaughter  tests  were  made  hy  Lawes  and  Gilbert, 
and  they  explain  in  part  why  a  fat  steer  is  worth  so 
much  more  per  pound  of  live  weight,  even  if  the  quality 
of  the  meat  is  no  higher.  It  may  be  said,  in  a  gen- 
eral way,  that  the  carcass  portion  of  the  animal  body 
varies  with  bovines  and  sheep  from  50  to  65  per  cent 
of  the  live  weight,  according  to  age  and  condition. 
Swine  "dress  away"  not  far  from  one -fifth. 

It  would  be  possible  to  go  further  in  our  discussion 
of  the  animal  body  and  consider  it  from  the  structural 
or  anatomical  point  of  view.  It  is  certainly  important 
to  know  something  of  the  organs  involved  in  digestion, 
respiration  and  assimilation  if  we  would  reach  a  clear 
understanding  of  how  the  food  is  made  available  and 
utilized,  but  such  facts  as  are  deemed  necessarj^  con- 
cerning these  specialized  tissues  we  will  take  up  in 
their  appropriate  connections. 


CHAPTER  VIII 

THE  DIGESTION  OF  FOOD 

We  have  accepted  so  far  without  discussion  the 
ahiiost  self-evident  fact  that  the  food  is  the  immediate 
source  of  the  energy  and  substance  of  the  animal  bod3^ 
It  now  remains  for  us  to  consider  the  waj^  in  which  the 
nutrition  of  an  animal  is  accomplished.  The  first  step 
in  this  direction  is  the  digestion  of  food.  It  is  necessary 
for  food  ingredients  to  be  placed  in  such  relations  to  the 
animal  organism  that  they  are  available  for  use.  This 
involves  both  condition  and  location.  The  various 
nutrients  in  the  exercise  of  their  several  functions  must 
be  generally  distributed  in  all  the  interior  parts  of  the 
animal.  It  is  obvious  that  hay  and  grain  as  such  cannot 
be  so  distributed,  and  so  their  compounds  must,  in  part 
at  least,  be  brought  into  a  soluble  and  diffusible  condi- 
tion, in  order  that  they  may  pass  through  the  mem- 
branous lining  which  separates  the  blood-vessels  and 
other  vascular  bodies  from  the  cavity  of  the  alimentary 
canal. 

In   discussing   phj^siological  relations  of   food,   two. 
terms  are  emploj^ed:    viz.,  digestion  and   assimilation. 
Digestion  refers  to  the  preparation  of  food  compounds 
for   use,    by   rendering    them    soluble    and    diffusible, 
changes  which  are  accomplished  in  what  we  call  the  ali- 

(98) 


Digestion  —  Ferments  99 

mentary  canal,  a  passage  that  begins  with  the  mouth, 
includes  the  stomach  and  intestines,  and  ends  with  the 
anus.  Assimilation  signifies  the  appropriation  of  nu- 
trients, after  digestion,  to  the  maintenance  of  energy 
and  to  the  building  of  flesh  and  bones,  processes  taking 
place  in  the  tissues,  to  which  the  nutritive  substances 
are  conveyed  by  the  blood.  The  two  terms  are  entirely 
distinct  in  meaning,  although  they  are  confused  in  popu- 
lar speech. 

In  digestion,  a  feeding  stuff  undergoes  both  mechani- 
cal and  chemical  changes.  It  is  masticated,  that  is, 
ground  into  finer  particles,  after  which,  in  its  passage 
along  the  alimentary  canal,  it  comes  in  contact  with 
several  juices  which  profoundly  modify  it  chemically. 
That  portion  of  it  which  is  rendered  diffusible  is  ab- 
sorbed by  certain  vessels  that  are  imbedded  in  the  walls 
of  the  stomach  and  intestines,  and  is  conveyed  into  the 
blood.  The  insoluble  part  passes  on  and  is  rejected  by 
the  animal  as  worthless  material,  and  constitutes  the 
solid  excrement  or  feces.  A  study  of  digestion  includes, 
then,  a  knowledge  of  mastication,  of  the  sources,  nature 
and  functions  of  the  several  digestive  juices,  and  a  con- 
sideration of  the  various  conditions  affecting  the  extent 
and  rapidity  of  digestive  action. 

FERMENTS 

The  changes  involved  in  rendering  food  compounds 
soluble  are  intimately  connected  with  a  class  of  bodies 
known  as  ferments,  to  which  brief  reference  has  already 
been  made  in  their  relations  to  the  preservation  of  feed- 


100  The  Feeding  of  Animals 

iiig  stuffs;  and  it  seems  necessary  before  proceeding  to 
a  consideration  of  digestion  as  a  process  to  learn  some- 
thing of  the  nature  and  functions  of  these  agents,  which 
are  actively  and  essentially  present  in  the  digestive  tract. 

A  ferment  may  be  defined  in  a  general  way  as  some- 
thing which  causes  fermentation;  in  other  words,  the 
decomposition  of  certain  vegetable  or  animal  compounds 
with  which  it  comes  in  contact  under  favorable  condi- 
tions. Ferments  are  of  two  kinds,  organized  and  unor- 
ganized. Organized  ferments  are  low,  microscopic  forms 
of  vegetable  life,  generally  single -celled  plants.  Unor- 
ganized ferments  are  not  living  organisms,  but  are  sim- 
ply chemical  compounds. 

When  milk  is  allowed  to  remain  in  a  warm  room  for 
several  hours  it  becomes  sour.  An  examination  of  it 
chemically  shows  that  its  sugar  has  largely  or  wholly 
disappeared  and  has  been  replaced  by  an  acid.  A  study 
of  the  milk  with  the  microscope,  before  and  after  sour- 
ing, reveals  the  fact  that  there  has  been  a  marvelous  in  - 
crease  in  it  of  single-celled  organisms  or  plants.  The 
growth  of  this  form  of  life  is  regarded  as  the  cause  of 
the  change  of  the  sugar  into  lactic  acid.  We  have  here 
the  so-called  lactic -acid  ferment,  which  may  tj^pify  the 
organized  ferments  known  as  bacteria.  Numerous  other 
fermentations  of  the  same  general  kind  are  common  to 
every-day  experience.  The  changes  in  the  cider  barrel 
and  the  wine  cask,  the  spoiling  of  canned  fruits  and 
vegetables,  and  the  heating  of  hay  and  grain  are  illus- 
trations of  what  is  accomplished  by  these  minute  organ- 
isms. Bacteria  that  cause  disease,  and  which  multiply 
in  the  organs  and  other  tissues  of  the  animal  body,  may 


IXgestion  —  Ferments  101 

also  be  properly  called  ferments,  because  in  their  growth 
new  compounds  are  formed  which  are  as  truly  fermenta- 
tive by-products  as  the  carbonic  acid  and  alcohol  of  cider 
and  beer  making.  As  this  subject  viewed  on  its  patho- 
genic side  is  not  important  to  the  feeder,  we  need  to 
study  organized  ferments  only  so  far  as  they  relate  to 
the  preservation  of  feeding  stuffs  and  to  changes  in  the 
alimentary  canal.  We  shall  be  best  equipped  for  con- 
trolling ferments  and  preventing  their  destructive  action 
if  we  know  what  they  are,  and  understand  the  general 
conditions  under  which  they  thrive.  We  should  also 
know  how,  and  to  what  extent,  their  action  occasions 
harm . 

The  organized  ferments  are  classed  in  the  vegetable 
kingdom.  As  a  rule,  each  individual  plant  is  a  single 
cell,  varying  in  shape  and  so  minute  as  to  be  invisible 
to  the  unaided  sight.  It  corresponds  in  its  general 
structure  to  the  cells  which  make  up  the  tissues  of  the 
higher  vegetable  species,  i.  e.,  it  consists  of  a  cell  wall 
inside  of  which  are  protoplasm  and  other  forms  of 
living  matter.  These  organisms  are  distributed  every- 
where,— in  the  air,  in  the  soil,  on  surfaces  of  plants 
and  in  the  bodies  of  animals.  Whenever  the  right 
opportunity  offers  itself,  they  are  ready  to  begin  to 
multiply  and  bring  about  all  the  results  attendant 
upon  their  growth. 

The  conditions  essential  to  their  development  are 
the  proper  degree  of  moisture  and  temperature  and 
the  necessary  food  materials.  Thoroughly  dry  animal 
and  vegetable  substances  do  not  ferment.  Hay  and 
grain  that  have   been   dried  to  a  water  content  of  10 


102  The  Feeding  of  Animals 

per  cent  will  keep  a  long  time  without  loss  from  fer- 
mentative changes.  The  heat  of  a  mow  of  new  hay 
or  of  a  bin  of  new  grain,  with  its  subsequent  musty 
condition,  is  due  to  the  fermentations  that  are  made 
possible  through  the  presence  of  considerable  moisture. 
Thorough  drying  is  a  preventive  of  destructive  fer- 
mentations. 

There  is  a  temperature  at  which  each  vegetable  fer- 
ment thrives  best,  and  there  are  limits  of  temperature 
outside  of  which  the  growth  of  these  forms  of  life  does 
not  occur,  or  is  "very  slight.  Numerous  species  thrive 
between  75°  and  100°  F.  Fermentable  materials  like 
fruit  and  meat  at  the  freezing  point  or  below  are  not 
subject  to  fermentations.  The  boiling  point  of  water 
kills  most  bacteria,  and  temperatures  above  150°  F. 
retard  or  entirely  prevent  their  growth. 

Like  all  life,  these  organisms  must  have  food. 
Many  species  find  this  in  acceptable  forms  in  vegetable 
products.  Because  they  generally  contain  the  sugar, 
albuminoids,  and  mineral  compounds  which  nourish 
bacteria,  feeding  stuffs  are  always  the  prey  of  ferments 
under  proper  conditions  of  moisture  and  heat.  The 
prevention  of  fermentation  in  cattle  foods  is  desirable 
because  it  occasions  a  loss  of  nutritive  value.  This 
becomes  evident  when  we  consider  the  nature  of  the 
chemical  changes  that  occur.  For  instance,  when  sugar 
is  broken  up  through  the  influence  of  a  bacterium,  new 
compounds  are-  formed  which  take  up  free  oxygen. 
This  means  that  combustion  occurs,  causing  the  lib- 
eration of  energy  which  otherwise  would  have  been 
available  to  the  animal,  if  the  sugar  had  been  taken 


Digestion  — Ferments  103 

as  food.  Many  fermentations  involve  oxidation,  all  of 
which  are  destructive  of  food  value. 

(Several  theories  have  been  advanced  to  account  for 
the  action  of  the  organized  ferments.  The  most  plausi- 
ble seems  to  be  that  these  little  plants  use  sugar 
and  other  compounds  as  food,  deriving  energy  there- 
from, the  carbonic  acid,  alcohol  and  other  new  bodies 
being  the  by-products  of  this  use.  Whatever  may  be 
the  real  explanation  of  the  changes  that  occur,  fer- 
mentations due  to  plant  growth  are  among  the  most 
useful  agencies  with  which  the  farmer  deals,  and  may 
be  the  most  harmful. 

There  is  another  class  of  ferments  which  is  termed 
unorganized,  and  to  which  the  general  name  enzym  is 
given.  These  are  the  ferments  especially  important  in 
digestion.  They  are  merely  chemical  compounds  which 
produce  a  peculiar  effect  upon  certain  bodies  with  which 
they  come  in  contact.  If  a  thin  piece  of  lean  beef  be 
suspended  in  an  extract  from  the  mucous  lining  of  a 
pig's  stomach,  to  which  has  been  added  a  small  pro- 
portion of  hydrochloric  acid,  the  liquid  being  kept  at 
about  98°  F.,  the  beef  will  soon  begin  to  soften,  after- 
wards swell  to  a  more  or  less  jelly-like  condition  and 
finally  dissolve.  The  same  general  result  would  occur 
with  fish,  blood  fibrin  or  the  coagulated  white  of  an 
Qg^.  When  starch,  which  is  not  affected  by  pure,  warm 
water,  is  placed  in  a  warm  water  solution  of  crushed 
malt  it  soon  dissolves,  leaving  a  comparatively  clear 
liquid.  A  chemical  examination  of  these  preparations 
will  reveal  the  fact  that  the  compounds  of  the  meat 
are  present   in   solution    in   somewhat    modified  forms, 


104  The  Feeding  of  Animals 

aud  that  the  starch  has  been  changed  to  a  sugar  or 
other  soluble  bodies.  In  both  cases  substances  insolu- 
ble   in  water  have  become  soluble  and  diffusible. 

The  cause  of  these  changes  is  the  presence  of  typical 
bodies,  one  in  the  pig's  stomach  and  one  in  the  malt, 
ferments  of  the  enzym  class,  the  former  of  which  ren- 
ders albuminoids  soluble,  the  latter  acting  to  produce 
a  similar  result  with  the  insoluble  carboh^-drates.  This 
action  is  different  from  that  of  the  organized  ferments, 
where  oxidation  occurs  in  many  cases.  The  enzym s 
simply  induce  the  albuminoids  and  starch  to  take  up 
the  elements  of  water,  which  apparently  does  not  greatly 
diminish  their  energy  value.  How  this  is  done  cannot 
be  explained  in  simple  terms,  if  at  all.  Our  knowledge 
of  the  manner  of  the  change  rests  entirely  upon  theo- 
retical grounds.  The  digestion  of  food  is  almost  wholly 
accomplished  through  the  specific  effect  of  enzym  bod- 
ies, of  which  every  digestive  fluid  contains  one  or 
more.  Examples  of  these  are  the  pepsin  and  pan- 
creatin  of  the  drug  store  that  contain  enzym s  mixed 
with  more  or  less  impurities.  The  function  of  each 
of  these  ferments  we  shall  consider  as  we  proceed  to 
discuss  the  various  steps  of  digestion. 

THE   MOUTH 

The  first  step  in  the  digestion  of  fodders  and  whole 
grains  is  to  reduce  them  to  a  much  finer  condition. 
This  is  done  in  the  mouth,  the  teeth  being  the  grind- 
ing tools.*     Sometimes  the  cutting  or  grinding  is  par- 

*This  is  not  true  of  hens,  turkeys  and  other  fowls. 


Digestion  —  The   Mouth  105 

tiallj'  or  wholly  performed  for  the  animal  in  hay-cutters 
and  grain  mills.  However  this  may  be  accomplished, 
it  is  an  essential  operation  for  two  reasons,  (1)  it  puts 
the  food  in  condition  to  be  swallowed,  and  (2)  fits  it 
for  the  prompt  and  efficient  action  of  the  several  diges- 
tive fluids.  Dr}'  whole  hay  or  kernels  of  grain  could 
hardly  be  forced  down  the  tube  leading  to  the  animal's 
stomach.  It  is  necessary  for  these  materials  to  be 
broken  down  and  moistened  in  order  that  they  may  be 
swallowed.  Even  if  they  could  be  conveyed  to  the 
stomach  in  their  natural  condition  the  process  of  ren- 
dering their  constituents  soluble  would  proceed  very 
slowly.  Common  experience  teaches  us  how  much 
more  quickly  finely  powdered  sugar  or  salt  will  dis- 
solve than  the  large  crystals  or  lumps.  The  more 
finely  any  solid  is  ground,  the  larger  is  the  surface  ex- 
posed to  the  attack  of  the  dissolving  liquid,  and  this  is 
as  true  of  foods  as  of  sugar  or  salt. 

Prompt  and  rapid  solution  of  food  is  essential,  be- 
cause if  it  is  too  long  delayed,  uncomfortable  and  in- 
jurious fermentations  are  likely  to  set  in,  and  because 
of  imperfect  digestion,  the  final  nutritive  effect  of  the 
ration  may  be  diminished.  For  these  reasons,  animals 
with  diseased  teeth,  or  those  that  have  lost  teeth, 
make  poor  use  of  their  food,  and  require  an  unneces- 
sary amount  to  keep  them  in  condition.  These  condi- 
tions may  often  be  a  cause,  especially  with  horses,  of 
disappointing  results  from  an  ordinarily  sufficient  ration. 

The  teeth  of  our  domestic  animals  differ  somewhat 
in  number  and  arrangement.  Authorities  state  the 
following  to  be  the  usual  number: 


106  The  Feeding  of  Animals 

Total  Incisors  Canines      Molars 

Horse 36-40  12                4            24 

Ox 32  8                             24 

Sheep  and  goat 32  8            24 

Pig 44  12       4     28 

The  incisors  or  front  teeth  are  those  which  are  used 
for  prehension,  and  by  grazing  animals  for  cutting  off 
the  grass  and  other  herbages.  With  the  ox,  sheep  and 
goat,  incisors  are  found  only  in  the  lower  jaw.  These 
shut  against  a  tough  pad  on  the  upper  jaw.  They  are 
constantly  wearing  off,  and  with  old  animals  may  be  so 
worn  away  as  to  leave  only  the  roots.  Such  animals 
do  not  graze  successfully.  With  the  horse  and  pig,  in- 
cisors are  found  in  equal  numbers  in  both  jaws. 

The  molars  are  the  grinding  teeth.  Those  of  the 
horse  sometimes  need  filing  on  the  outside  edges  in 
order  to  prevent  irritation  and  soreness  of  the  adjacent 
tissues.  A  diseased  molar  may  occasion  an  animal 
much  discomfort  and  cause  imperfect  mastication. 

During  mastication  there  is  poured  into  the  mouth 
a  liquid  called  the  saliva,  which  has  two  important 
functions:  (1)  it  moistens  the  food,  and  (2)  with  sev- 
eral species  of  animals  it  causes  a  chemical  change  in 
certain  of  the   constituents   of  the  food. 

The  saliva  has  its  origin  in  several  secretory  glands 
that  are  adjacent  to  the  mouth  cavity,  and  from  these 
this  liquid  is  poured  into  the  mouth  through  ducts  that 
open  in  the  cheek  under  the  tongue.  The  chief  of 
these  glands  are  located  in  the  side  of  the  face,  below 
and  somewhat  back  of  the  jaws  and  beneath  the  tongue, 
and  are  called  the  parotid,   the  submaxillary  and  the 


Digestion — The   Mouth  107 

sublingual.  Other  glands  of  this  character  are  scat- 
tered in  the  cheeks  and  at  the  base  of  the  tongue. 
The  anatomj^  and  arrangement  of  these  organs  are  not 
essential  to  our  subject.  We  are  chiefly  interested  in 
the  liquid  which  they  secrete. 

The  saliva  is  a  transparent  and  somewhat  slimy 
liquid,  and  contains  generally  not  less  than  99  parts 
in  100  of  water,  and  one  part  or  less  of  solid  matter. 
It  is  alkaline  in  reaction,  because  of  the  presence  of 
compounds  of  the  alkalies.  The  specific  chemical  effect 
exerted  by  this  liquid  on  the  food  constituents  may 
be  illustrated  by  subjecting  starch  to  its  action.  When 
this  is  done,  the  starch  gradually  disappears  as  such 
and  is  replaced  by  maltose,  the  same  sugar  that  we 
find  in  barley  malt.  The  chemist  has  learned  that 
the  agent  which  is  active  in  causing  this  change  is 
a  ferment,  to  which  the  name  ptyalin  has  been  given, 
and  which  is  always  present  in  the  saliva  of  man  and 
of  some  animals.  It  is  classed  among  the  diastatic 
ferments,  because  it  has  an  office  similar  to  that  of 
diastase  in  the  germination  of  seeds;  viz.,  the  trans- 
formation of  the  starch  into  a  sugar.  This  change 
begins  in  the  mouth  and  probably  continues  in  the 
stomach  until  the  food  becomes  so  acid  that  the  fer- 
ment ceases  to  act,  for  ptyalin  is  inactive  except  in 
an  alkaline  medium.  There  is  no  reason  for  supposing 
that  any  considerable  proportion  of  the  starch  of  a 
ration  is  transformed  by  the  saliva,  but  this  solvent 
action  which  continues  later  in  the  digestive  processes 
certainly  begins  in  the  mouth  in  the  manner  described. 

The  saliva  also  moistens  the  food,  which  is  a  most 


108  The  Feeding  of  Animals 

irapoi'tant  office,  for  it  is  a  necessary  preparation  to  the 
act  of  swallowing.  With  large  ruminants,  the  quantity 
of  saliva  required  for  this  purpose  is  large,  as  is  evident 
when  we  remember  that  an  ox  or  cow  may  consume  in 
one  day  24  pounds  of  very  dry  hay  and  grain,  and  that 
rumination  goes  on  much  of  the  time  while  the  animal 
is  not  eating.  It  is  estimated  that  oxen  and  horses  se- 
crete from  88  to  132  pounds  daily,  an  apparently  enor- 
mous quantity  of  liquid  for  secreting  organs  no  larger 
than  the  salivary  glands  to  supply. 

THE    STOMACH 

When  the  food  leaves  the  mouth,  it  passes  down  the 
gullet  (oesophagus)  into  the  stomach.  The  only  modi- 
fications it  has  suffered  up  to  this  point  are  its  reduction 
to  a  finer  condition  and  a  slight  action  of  the  mouth 
ferment  upon  the  starch,  an  influence  which  doubtless 
continues  in  the  stomach  for  a  larger  or  shorter  pe- 
riod, according  to  circumstances.  After  the  food  is 
swallowed  changes  of  another  kind  begin  sooner  or 
later,  affecting  the  protein  compounds  especially. 

Before  considering  gastric;  digestion  from  a  chemi- 
cal point  of  view,  we  should  become  acquainted  with 
the  widely  differing  structure  of  the  stomachs  of  the 
various  farm  animals.  Those  of  the  ox  and  horse  are 
greatly  unlike.  The  stomach  of  the  ox,  and  of  all  other 
ruminants,  consists  of  four  divisions  or  sacs,  whereas 
with  the  horse  and  pig  it  is  made  up  of  a  single  sac. 

The  ruminant  stomach  is  really  quite  a  complicated 
affair,  and  the  way  in  which  it  disposes  of  the  food  is 


Digestion — The  Stomach  109 

understood  onh'  after  a  careful  study  of  details.  Its 
four  divisions  or  sacs  are  the  paunch,  honeycomb, 
many -plies  and  rennet,  or  what  the  physiologist  has 
named  the  rumen,  reticulum,  omasum  and  abomasum. 
With  the  ox  these  cavities  contain  on  the  average  not 
far  from  fifty -five  gallons,  about  nine -tenths  of  this 
space  belonging  to  the  paunch.     Fig.  1. 


Fig.  1.    Stomach  of  ox. 
T,  rumen  or  paunch,  showing  attachment  of  oesophagus. 
C,  reticulum  or  honeycomb. 
O,  omasum  or  many-plies. 
A,  abomasum  or  rennet,  showing  attachment  of  small  intestine. 

The  food,  in  its  descent  from  the  mouth,  passes  at 
first  mostly  into  the  paunch  through  a  slit  in  the  gul- 
let. This  cavity,  as  stated,  is  very  large,  and  it  may 
properly  be  considered  as  an  immense  reservoir  for  the 
storage  of  the  bulky  materials  which  the  ruminants 
take  as  food.  As  is  the  case  with  the  entire  digestive 
canal,  the  walls  of  the  paunch  are  composed  of  three 
layers    of   tissue,   the    middle    one    being   a  very  thick 


110  The  Feeding  of  Animals 

muscular  coat,  which  seems  necessary  to  produce  the 
movement  of  large  masses  of  food.  The  inner  or 
mucous  layer  is  covered  with  numerous  leaflike  pro- 
jections, in  which  the  blood-vessels  are  freely  distrib- 
uted. During  its  stay  in  this  reservoir,  the  moist  food 
becomes  thoroughly  softened  and  besides  undergoes  a 
variety  of  changes,  chiefly  those  due  to  the  organized 
ferments  combined  perhaps  with  the  continued  action 
of  the  saliva.  These  fermentations  cause  an  almost 
constant  evolution  of  gases,  which  are  as  constantly 
absorbed  by  the  blood.  It  is  suggested  that  the  rapid 
puffing  up  of  the  paunch  of  a  freshly -killed  bovine  is 
due  to  the  failure  of  the  blood  to  take  up  these  gases. 
Sometimes  unnatural  and  dangerous  fermentations  set 
in,  induced  often  by  the  consumption  in  the  spring  of 
a  large  quantity  of  easily  fermentable  food  such  as 
green  clover.  This  causes  hoven,  and  unless  the  gas 
pressure  is  at  once  relieved  by  an  opening  into  the 
paunch  the  animal  dies,  often  after  the  bursting  of  the 
rumen. 

A  portion  of  the  food  reaches  the  reticulum  or 
honeycomb,  either  through  the  oesophagal  slit  when 
first  swallowed,  or  through  a  large  opening  between 
the  paunch  and  the  honeycomb.  The  reticulum  also 
communicates  with  the  third  stomach  by  an  opening. 
This  is  the  smallest  division  of  the  stomach,  and  de- 
rives its  common  name  from  the  fact  that  its  interior 
surface  is  divided  by  ridges  of  the  mucous  membrane 
into  cells  which  bear  a  close  resemblance  to  a  honey- 
comb. These  cells,  which  are  several  sided  and  quite 
deep,  appear  to  be  a  "catch-all"  for  the  foreign  bodies 


Digestion— The   Stomach  111 

which  animals  are  liable  to  swallow,  such  as  small 
stones,  pins  and  nails.  The  contents  of  this  compart- 
ment of  the  stomach  are  very  watery,  a  condition  which 
is  said  to  aid  the  return  of  the  food  to  the  mouth,  por- 
tion by  portion,  for  remastication. 

Rumination,  which  is  the  re -chewing  of  food  pre- 
viously swallowed,  is  peculiar  to  bovines,  sheep  and 
goats.  In  the  case  of  these  species,  the  mastication  of 
coarse  fodder  is  not  completed  before  it  is  swallowed 
the  first  time,  and  they  have  the  power  of  returning  to 
the  mouth  the  material  which  has  become  stored  in  the 
paunch  and  honeycomb  in  order  that  it  may  be  more 
finely  ground.  This  is  what  is  termed  "chewing  the 
cud."  It  is  an  operation  which  greatly  aids  digestion 
in  rendering  the  food  mass  finer  and  more  susceptible 
to  the  action  of  the  digestive  fluids.  Animals  fed  on 
grain  alone  do  not  ruminate.  They  "lose  their  cud," 
a  condition  popularly  and  erroneously  supposed  to  be 
fatal  to  the  animal's  life. 

After  remastication,  the  food  does  not  return  wholly 
to  the  first  and  second  stomachs,  but  is  mostly  carried 
along  in  what  is  known  as  the  cesophagal  groove  to  the 
third  stomach,  the  omasum.  The  finer  portions  may 
even  do  this  when  first  swallowed.  The  many -plies 
(omasum)  is  a  cavity  somewhat  larger  than  the  honey- 
comb, which  has  a  most  curious  interior  structure.  It 
is  filled  with  extensions  of  the  mucous  membrane  in 
the  form  of  leaves,  between  which  the  food  passes  in 
thin  sheets,  an  arrangement  which  seems  to  have  for 
its  purpose  the  further  grinding  of  the  food  so  that 
when  it    finally  reaches  the  fourth  and   last  compart- 


112  The  Feeding  of  Animals 

ment  it  is  in  a  very  finely -divided  condition  and  is 
thoroughly  prepared  for  the  action  of  the  juices  that 
are  subsequently  poured  upon  it. 

It  is  at  the  last  stage  of  the  journey  of  the  food 
through  this  complicated  stomach  that  it  is  submitted 
to  the  true  gastric  digestion.  As  a  matter  of  fact,  the 
abomasum  or  rennet  is  regarded  as  the  true  stomach, 
the  other  three  sacs  being  considered  as  enlargements  of 
the  oesophagus.  In  the  calf,  the  rennet  is  the  only  part 
developed,  the  other  divisions  not  coming  into  use 
until  the  animal  takes  coarse  foods  in  considerable 
quantity.  The  fourth  stomach  is  larger  than  either 
the  second  or  third.  It  receives  directly  from  the 
omasum  the  finely  divided  food,  upon  which  it  pours 
the  gastric  juice,  a  liquid  that  is  secreted  in  large 
quantity  by  glands  located  in  its  inner  or  mucous 
membrane.  This  juice,  like  all  the  digestive  fluids, 
is  mostly  water,  the  proportion  being  between  98 
and  99  parts  to  less  than  two  parts  of  solids.  The 
latter  consist  of  ferments,  a  certain  amount  of  free  or 
uncombined  hydrochloric  acid  and  a  variety  of  mineral 
compounds,  prominent  among  which  are  calcium  and 
magnesium  phosphates  and  the  chlorides  of  the  alka- 
lies, common  salt  being  especially  abundant. 

Especial  interest  pertains  to  the  ferments  of  the  gas- 
tric juice,  one  of  which,  in  connection  with  free  hydro- 
chloric acid,  causes  a  most  important  change  in  the  . 
proteids  of  the  food  by  reducing  albuminoids,  such  as 
the  gliadin  and  glutenin  of  the  wheat  kernel  to  soluble 
forms.  We  know  quite  definitely  about  this  action, 
because  it  can  be  very  successfully  produced  in  an  ar- 


Digestion — The   Stomach  113 

tifieially  prepared  liquid.  If  the  raucous  lining  of  a 
pig's  stomach,  after  carefully  cleaning  without  washing 
with  water,  is  warmed  for  some  hours  in  a  very  dilute 
solution  of  hydrochloric  acid,  an  extract  is  obtained 
which  has  the  power  of  dissolving  lean  meat,  wheat 
gluten  and  other  proteid  substances.  The  active  agent 
in  causing  this  solution  is  pepsin,  an  unorganized  fer- 
ment or  enzym  which  is  present  in  the  gastric  fluid  of 
all  animals.  It  changes  albuminoids  to  peptones,  bod- 
ies so  soluble  and  diffusible  that  they  pass  readily  into 
certain  small  vessels  which  are  distributed  in  the  walls 
of  the  alimentary  canal  and  thus  become  available  as 
nutrients.  The  other  ferment  present  in  the  gastric 
juice  is  the  one  which  gives  to  rennet  its  value  as  a 
means  of  coagulating  the  casein  of  milk  in  cheese- 
making,  and  is  called  rennin.  The  action  of  this  latter 
body  is  especially  prominent  in  the  stomach  of  the  calf 
when  fed  exclusively  on  milk,  and  it  is  the  calf's  active 
stomach,  the  fourth  in  the  mature  animal,  which  is  the 
source  of  commercial  rennet. 

The  free  hydrochloric  acid  in  the  gastric  juice  is  also 
actively  concerned  in  proteid  digestion.  It  is  found 
that  a  solution  of  pepsin  has  little  or  no  effect  in  the 
absence  of  free  acid,  for  when,  during  artificial  diges- 
tion, the  supply  of  this  acid  is  used  up  it  must  be 
renewed  or  digestion  ceases. 

The  stomach  of  the  horse  and  pig  consists  of  a 
single  sac,  so  that  digestion  with  these  animals  is  a 
much  simpler  matter  mechanicallj-  than  with  ruminants. 
Chemically,  the  results  are  essentially  similar,  i.  e.,  the 
protein  is  in  part  changed  to  peptones.    The  food,  after 

H 


114  The  Feeding  of  Animals 

being  swallowed,  is  not  returned  to  the  mouth,  but  is 
very  soon  brought  under  the  action  of  the  gastric  juice 
without  so  long- continued  pre- 
liminary preparation  by  remas- 
tication  and  trituration.  For 
this  reason  the  horse  fails  to 
digest  coarse  fodders  so  com- 
pletely as  the  ox  does.  Besides, 
the  stomachs  of  the  horse  and 
pig  are  too  small  to  admit  of 
so  large  an  ingestion  of  hay  or 
u=^^^/>-  similar  material,  as  is  the  case 

Fig.  2.    stomach  of  horse.  . .,  .  ,  n       •      -i 

„        ,      ,        ,  with  ruminants  ot  similar  size. 

B,  oesopnagal  attachment. 

A,  pyloric  end  of  stomach,  with    lu     all     SpCCicS,     hoWCVCr,     the 
beginning  of  small  intestine.      digmical      rCSUlt     of     stOUiach 

digestion  is  essentially  the  same,  i.  e.,  the  protein  is  in 
part  changed  to  peptones.     Fig.  2. 

THE    INTESTINES 

The  most  extended  portion  of  the  alimentary  canal, 
though  not  the  most  capacious  in  all  cases,  is  the  in- 
testines. They  consist  of  a  tube  differing  in  size  in  its 
various  portions,  which  begins  with  the  stomach  and 
ends  with  the  anus.  This  tube  is  not  a  straight  passage 
between  the  points  named,  but  presents  curves  and 
folds,  so  that  when  straightened  out  it  appears  sur- . 
prisingly  long.  Its  average  length  with  the  ox  is  given 
as  187  feet,  sheep  107  feet,  horse  98  feet,  and  hog 
77  feet,  lengths  which  are  from  twelve  to  twenty- 
seven  times  that  of  the  body  of  the  animal.    The  intes- 


I 


Digestion —  The  Intestines  115 

tines  are  divided  into  large  and  small,  the  latter  being 
from  three  to   four  times  as  large  as  the  former. 

When  the  food  leaves  the  stomach,  it  enters  the 
small  intestines.  At  this  point  it  is  only  partially 
digested.  The  fats  are  probably  so  far  unchanged  and, 
without  doubt,  the  larger  proportion  of  the  proteids 
and  carbohydrates  that  are  susceptible  of  solution  is 
still  in  the  original  condition.  Hardly  has  this  par- 
tially dissolved  material  passed  into  the  small  intes- 
tines before  it  comes  in  contact  with  two  new  liquids 
which  are  poured  upon  it  simultaneously  or  nearly  so; 
viz.,  the  bile  and  the  pancreatic  juice,  and  the  changes 
which  began  in  the  mouth  and  stomach,  together  with 
others  which  set  in  for  the  first  time,  proceed  vigor- 
ously. 

The  bile  has  its  source  in  the  liver.  It  is  a  secre- 
tion of  this  organ,  and  after  elaboration  it  is  stored  in 
a  small  sac  attached  to  the  liver  which  is  called  the 
"gall  bladder,"  and  from  which  gall  is  conveyed  to 
the  intestines  through  a  duct  opening  very  near  the 
orifice  leading  out  of  the  stomach.  Bile  is  a  liquid 
varying  when  fresh  from  a  golden  red  color  in  man 
to  a  grass -green  or  olive -green  in  certain  herbiverous 
animals.  It  is  slightly  alkaline,  bitter  to  the  taste 
and  without  odor.  The  specific  and  characteristic  con- 
stituents of  the  bile  are  two  acids,  glycocholic  and 
taurocholic,  that  are  combined  with  sodium  and  are 
associated  with  two  coloring  matters,  bilirubin  and 
biliverdin.  Numerous  other  compounds  are  present 
in  very  small  proportions,  such  as  fats,  soaps  and  min- 
eral compounds,  but  they  appear  to  have  no  important 


116  The  Feeding  of  Animals 

relation  to  digestion.  If  any  ferment  is  present  at  all, 
it  is  only  as  a  trace,  and  therefore  the  bile  is  incapable 
of  effecting  decomposition  of  the  proteids  and  carbo- 
hydrates, snch  as  occnr  in  the  mouth  and  stomach. 
This  is  shown  by  experiments. 

Nevertheless,  this  liquid  must  be  regarded  as  having 
a  real  digestive  function,  which  it  exerts  in  two  ways, 
(1)  by  preparing  the  chyme  (partially  digested  food 
from  the  stomach)  for  the  action  of  the  pancreatic  juice 
and  (2)  in  acting  upon  the  fats  in  such  a  way  as  to 
render  their  absorption  possible. 

We  have  learned  that  pepsin,  the  stomach  ferment, 
acts  upon  proteids  only  in  an  acid  medium.  The  oppo- 
site is  true  of  the  ferments  which  the  food  meets  in  the 
intestines,  for  these  require  an  alkaline  condition.  The 
bile  tends  to  neutralize  the  acidity  of  the  chyme,  and  in 
this,  as  W'Cll  as  by  other  chemical  changes  too  complex 
for  discussion  here,  prepares  the  way  for  the  pancreatic 
juice  to  do  its  work. 

The  most  important  discovery  so  far  made  in  con- 
nection with  the  bile  is  the  fact  that  when  its  entrance 
into  the  intestines  is  prevented  the  fat  of  the  food 
largely  passes  off  in  the  feces.  This  proves  that  in 
some  way  the  liver  secretion  is  essential  to  the  digestion 
of  fats.  The  ordinary  and  probably  correct  explanation 
of  what  takes  place  is  that,  while  bile  does  not  decom- 
pose the  fats  in  any  way,  it  is  able,  in  connection  with, 
certain  influences  of  the  pancreatic  juice,  to  reduce  them 
to  an  emulsion,  i.  e.,  to  a  condition  of  suspension  in  a 
liquid  in  very  finely  divided  particles,  a  form  in  which 
they  are  able  to  pass  into  the  blood.      It  is  believed 


Digestion  —  Intestines  117 

that  the  bile  has  more  or  less  antiseptic  influence  and 
so  prevents  the  intestinal  contents  from  undergoing 
putrefactive  fermentation,  which  would  have  the  effect 
of  greatly  increasing  the  offensive  odor  of  the  feces. 

The  pancreatic  juice  has  a  more  complex  function 
in  digestion  than  that  of  any  other  digestive  fluid.  It 
is  known  to  contain  at  least  three  distinct  ferments, 
each  of  which  has  its  own  peculiar  effect  upon  each  of 
the  three  classes  of  food  constituents.  This  juice  reaches 
the  food  at  practically  the  same  time  as  the  bile.  It 
comes  from  the  pancreas,  a  gland  known  to  butchers 
as  the  "sweet  bread,"  and  enters  the  intestine  through 
a  small  duct  which  in  some  animals  is  Qonfluent  with 
the  bile  duct.  It  is  somewhat  gluey  in  character,  of 
alkaline  reaction  and  has  a  saltish  taste. 

First  of  all,  the  pancreatic  juice  has,  in  a  marked 
degree,  the  power  of  digesting  proteids  in  an  alkaline 
medium.  This  power  is  due  to  a  ferment  known  as 
trypsin,  which  converts  proteids  to  peptones,  and  cor- 
responds in  its  function,  therefore,  to  the  pepsin  of 
the  stomach.  Under  the  influence  of  this  ferment  the 
proteids  are  also,  to  some  extent,  split  into  simpler 
bodies. 

The  transformation  of  starch  into  sugar  and  other 
soluble  bodies,  which  ceased  in  the  stomach,  is  again 
taken  up  through  the  influence  of  a  diastatic  ferment 
present  in  the  pancreatic  juice,  and  proceeds  vigorously. 
A  third  enzym,  also  present,  is  one  that  has  the  power 
of  splitting  the  neutral  fats  into  fatty  acids  and  glycer- 
ine, a  change  which  appears  to  have  an  important  rela- 
tion to  the  emulsionizing  of  fats.     As  before  intimated, 


118  The  Feeding  of  Animals 

the  bile  aud  the  pancreatic  juice  appear  to  share  the 
fuuctiou  of  fat  digestion. 

As  the  intestinal  contents  pass  along,  they  come  in 
contact  with  a  juice  secreted  by  the  walls  of  the  intes- 
tines, the  action  of  which  has  been  carefully  studied. 
It  has  been  found  that  this  liquid  has  no  action  on  the 
proteids  or  fats,  but  that  it  is  able  to  convert  starch 
into  soluble  bodies,  and  especiallj^  has  the  peculiar  prop- 
erty of  transforming  into  glucose  the  maltose  arising 
from  previous  digestion,  glucose  being  the  form  in 
which  all  digested  carbohydrates  are  supposed  to  enter 
the  circulation.  It  seems,  then,  that  the  intestinal  juice 
supplements  {lie  action  of  the  other  digestive  fluids,  so 
far  as  carbohydrates  are  concerned,  completing  starch 
digestion  and  preparing  the  sugars  for  absorption,  and 
when  we  consider  that  from  80  to  90  per  cent  of  tlie 
food  of  our  farm  animals  consists  of  carbohydrates  the 
great  importance  of  this  office  is  apparent. 

From  the  time  the  food  enters  the  stomach  untilthe 
undigested  residue  leaves  the  body  the  contents  of  the 
alimentary  canal  are  subjected  to  fermentations  caused 
by  organized  ferments,  resulting  in  the  evolution  of 
acids,  gases  and  certain  other  compounds  formed  from 
the  proteids,  which  give  to  the  feces  its  offensive  odor. 
Just  what  relation  these  fermentations  have  to  the  di- 
gestion of  food  we  are  not  able  to  state.  There  are 
strong  reasons  for  believing  that  crude  fiber  (cellulose), 
during  its  stay  in  the  first  stomach,  is  the  subject  of 
their  action,  and  its  digestion  may  be  wholly  brought 
about  in  this  way.  Such  fermentations  become  promi- 
nent only  when,  because  real  digestion  does  not  proceed 


Food  Ahsor}}iion  119 

normally,  they  are  given  an  opportunity  to  deveiop  with 
unusual  activity  and  cause  bloat,  colic  and  offensive 
odors  in  the  solid  excrement. 

ABSORPTION    OF    THE    FOOD 

From  the  time  the  food  enters  the  stomach,  during 
nearly  its  entire  course  along  the  alimentary  canal,  there 
is  a  constant  production  of  soluble  compounds,  which 
progressively  disappear  into  other  channels,  so  that  when 
the  anus  is  reached  only  a  portion  of  the  original  diy 
matter  is  found  in  the  residue.  In  some  waj',  not  wholly 
explainable  in  all  its  details,  the  digested  food  has  been 
absorbed  and  received  into  vessels  through  which  it  is 
distributed  to  the  various  parts  of  the  bodj*. 

A  merely  casual  observation  shows  us  that  the  inner 
surface  of  the  walls  of  the  digestive  organs  are  covered 
by  numerous  projections.  The  anatomist,  by  a  careful 
study  of  these,  has  learned  that  imbedded  in  their  tis- 
sue, especially  in  the  intestines,  are  the  minute  branches 
of  two  systems  of  vessels.  One  set  is  the  lacteals  be- 
longing to  the  so-called  lymphatic  sj'stem  and  the  other 
set  is  the  capillaries  of  the  blood  system.  The  lym- 
phatic vessels  or  tubes  all  lead  to  a  main  tube  or  reser- 
voir, the  thoracic  duct,  which  extends  along  the  spinal 
column  and  finally  enters  one  of  the  main  blood-vessels. 
Any  material,  therefore,  taken  up  by  the  lacteals  ulti- 
mately reaches  the  blood.  The  capillaries  all  converge 
to  a  larger  blood-vessel,  known  as  the  portal  vein,  which 
enters  the  liver,  carrying  with  it  whatever  material  the 
capillaries  have  absorbed. 


120  The  Feeding  of  Animals 

The  manner  in  which  the  soluble  food  is  absorbed 
may  be  explained  in  part  on  common  physical  grounds. 
When  two  solutions  of  different  densities,  containing 
diffusible  compounds,  are  separated  by  a  permeable 
membrane,  diffusion  through  this  membrane  from  the 
denser  to  the  lighter  liquid  will  always  occur.  Such  a 
condition  as  this  prevails  in  the  intestines,  we  may  be- 
lieve. The  intestinal  solution,  the  denser  one,  is  sep- 
arated from  a  less  concentrated  liquid,  the  blood,  which 
is  constantly  flowing  on  the  other  side  of  a  thin  dividing 
membrane.  Under  these  conditions  only  one  thing  can 
occur;  viz.,  the  passage  into  the  blood  of  certain  parts 
of  the  digested  food.  It  is  held  that  in  this  way  w^ater, 
soluble  mineral  salts  and  sugar  pass  directly  into  the 
blood-vessels.  The  peptones  are  taken  np  largely  by 
lacteals  and  the  fats  enter  the  blood  entirely'  through 
this  channel. 

In  the  absorption  of  peptones,  ^^e  encounter  forces 
other  than  those  which  pertain  to  the  mere  diffusion  of 
liquids,  the  operation  of  which  is  still  more  or  less 
shrouded  in  mystery.  As  we  have  learned,  the  proteids 
are  largely  changed  to  peptone  in  the  stomach  and  in- 
testines, but,  strange  as  it  may  seem,  no  peptone  is 
found  in  the  blood.  At  some  point  in  its  passage 
through  the  lining  tissues  of  the  digestive  tract,  it  has 
been  regenerated  into  forms  more  nearly  like  those  from 
which  it  is  derived.  Moreover,  the  absorption  of  fats 
is  regarded  as  being  accomplished  through  the  activity 
of  certain  cells  or  corpuscles,  which  appear  to  convey 
tliis  portion  of  the  food  to  the  lacteals.  It  seems,  then, 
that  the  vital  forces  residing  in  the  living  animal  cells 


Undigested  Residue — Why  Digestibility  Varies     121 

play  a  part  in  transferring  the  nutrients  into  the  blood 
circulation,  and  that  this  absorption  can  no  longer  be 
e .       explained  wholly  on  physical  grounds. 

FECES 

The  soluble  and  insoluble  portions  of  the  intestinal 
contents  become  separated  gradually,  and  the  undissolved 
part  arrives  finally  at  the  last  stage  of  its  journey  along 
the  alimentar}' canal  and  is 'expelled  as  the  solid  excre- 
ment or  feces.  This  is  made  up  of  the  undigested  food 
and  a  small  proportion  of  other  matter,  such  as  residues 
from  the  bile  and  other  digestive  juices,  mucus  and 
more  or  less  of  the  epithelial  cells,  which  have  become 
detached  from  the  walls  of  the  stomach  and  intestines. 
Very  small  quantities  of  fermentation  products  are 
present  also,  which  give  to  the  feces  its  offensive  odor. 
The  incidental  or  waste  products  may  properly  be  con- 
!  sidered  as  belonging  to  the  wear  and  tear  of  digestion 

THE    RELATION    OP    THE    DIFFERENT    FEEDING    STUFF 
COMPOUNDS    TO    THE    DIGESTIVE    PROCESSES 

Numerous  digestion  experiments  with  a  large  variety 
of  feeding  stuffs  have  abundantly  established  the  fact 
that  these  materials  differ  greatly  in  their  solubility  in 
the  digestive  juices.  This  is  an  important  matter,  and 
one  which  should  be  well  understood,  for  we  must  con- 
sider both  the  weight  of  a  ration  and  its  availability 
in  determining  its  nutritive  value.  Variations  in  diges- 
tibility are  caused  primarily  by  variations  in  composi- 


122  The  Feeding  of  Anhndls 

tioD.  The  low  digestibility  of  wheat  straw,  as  compared 
with  that  of  the  wheat  kernel,  is  due  to  the  absence  in 
one  of  compounds  that  are  abundant  in  the  other.  We, 
therefore,  must  deal  fundamentally  with  the  suscepti- 
bility of  the  various  single  constituents  of  plants  to  the 
dissolving  action  of  the  several  digestive  ferments. 

In  this  connection,  we  need  to  pay  little  attention  to 
the  mineral  compounds.  They  do  not  undergo  fermen- 
tative changes  in  the  way  that  the  carbon  compounds 
do,  but  pass  into  simple  solution  either  in  the  water 
accompanying  the  food,  or  in  the  juices  with  which  they 
come  in  contact. 

As  has  been  noted,  protein  is  a  mixture  of  nitrog- 
enous compounds,  largely  albuminoids.  The  gluten  of 
wheat  contains  at  least  five  of  these  bodies,  and  other 
seeds  as  many.  What  is  the  relative  susceptibility  of 
these  single  proteids  to  ferment  action  either  as  to  ra- 
pidity or  completeness  of  change  does  not  appear  to  be 
known.  Some  albuminoids  are  practically  all  digested 
by  artificial  methods,  and  probably  are  in  natural  di- 
gestion. It  is  a  fact,  however,  that  protein  is  much 
more  completely  dissolved  from  some  feeding  stuffs  than 
from  others.  That  of  milk  is  all  digestible,  that  of  some 
grains  very  largely  so,  while  with  the  fodders  quite  a 
large  proportion  escapes  solution.  Whether  this  is  due 
to  a  differing  degree  of  solubility  on  the  part  of  the 
characteristic  protein  compounds  of  these  feeding  stuffs 
is  not  quite  determined.  The  fact  that  highly  fibrous 
materials  show  the  lowest  proportion  of  digestible  pro- 
tein suggests  as  an  explanation  that  the  nitrogen  com- 
pounds of  the  coarse  fodders  are  so  protected  by  the 


WJiy  Digestibility   Varies  123 

large  amount  of  fiber  present  that  they  escape  the 
full  action  of  the  digestive  juices.  It  is  certain,  anyway, 
that  the  protein  of  3'oung  and  tender  tissues  and  of  the 
grains  is  more  fully  digested  than  that  of  the  hays  and 
straws. 

In  the  case  of  the  carbohydrates,  our  knowledge  of 
the  relative  susceptibility  of  the  individual  compounds 
to  enzym  action  is  more  definite.  First  of  all,  the  nec- 
essary modification  of  the  sugars,  which  are  alreadj- 
soluble,  is  slight,  and  they  are  wholly  digested.  In  the 
second  place,  we  have  learned  in  two  ways  that  the 
starches  are  wholly  transformed  to  diffusible  compounds, 
first  by  submitting  them  in  an  artificial  way  to  the  ac- 
tion of  various  diastatic  ferments,  and,  second,  by  dis- 
covering a  complete  absence  of  starch  or  its  products  in 
the  feces  of  our  domestic  animals.  In  no  case  that  has 
come  under  the  writer's  notice  has  either  starch  or  sugar 
been  found  in  the  solid  excrement.  We  can  say,  there- 
fore, that  under  normal  conditions  the  starches,  like  the 
sugars,  are  completely  digestible. 

Digestibility  must  be  considered,  however,  from  the 
standpoints  both  of  rapidity  and  of  completeness.  As 
to  the  former  factor,  starches  from  unlike  sources  ex- 
hibit some  remarkable  differences.  Investigations  by 
Stone,  who  submitted  a  number  of  these  bodies  to  the 
action  of  several  diastatic  ferments,  show  that  "this 
variation  reaches  such  a  degree  that  under  precisely  the 
same  conditions  certain  of  the  starches  require  eighty 
times  as  long  as  others  for  complete  solution."  The 
potato  starches  appear  to  be  acted  upon  much  more 
rapidly  than  those  from  the  cereal  grains. 


124  The  Feeding  of  Animals 

Other  carbohydrates  and  related  substances,  such 
as  the  gums  and  cellulose,  do  not  undergo  complete 
digestion,  sometimes  half  or  more  of  these  compounds 
escaping  solution.  Stone,  after  examining  twenty  feed- 
ing stuffs  and  the  fecal  residues  obtained  from  them  in 
digestion  experiments,  found  in  the  feeding  stuffs  from 
6  to  16  per  cent  of  gums,  46  to  77  per  cent  of  which 
was  digested,  the  average  being  58  per  cent.  Crude 
fiber  proves  to  be  digestible  Avithin  about  the  same 
limits,  or  36  to  80  per  cent  with  American  fodders.  We 
are  much  in  tlie  dark  concerning  the  manner  of  diges- 
tion of  the  gums  and  crude  fiber.  To  what  extent 
these  substances  are  the  subjects  of  purely  fermentative 
changes,  or  of  merely  chemical  decompositions,  is  not 
known  at  present,  but  the  fact  of  a  partial  digestion  is 
well  established  whatever  may  be  the  causes  involved. 

The  extent  of  the  digestion  and  absorption  of  the 
fats  or  oils  is  also  not  definitely  known.  If  we  were  to 
accept  the  figures  given  for  ether  extract  in  tables  of 
digestion  coefficient  as  applying  to  the  real  fats  we 
would  believe  that  their  digestibility  varies  from  less 
than  one -third  to  the  total  amount.  It  is  unfortunatelj' 
true  that  these  coefficients  mean  but  very  little.  The 
ether  extract  from  the  feeding  stuffs  is  only  partially 
fat  or  oil,  as  w^e  have  seen,  and  the  inaccuracy  of  a 
digestion  trial  is  still  further  aggravated  by  the  pres- 
ence in  the  feces  of  bile  residues  and  other  bodies  which 
are  soluble  in  ether,  so  that  the  difference  between  the 
ether  extract  in  the  ration  and  that  in  the  feces  gives 
us  little  information  as  to  what  has  happened  to  the 
actual  fats.     It  seems  very  probable  that  pure  vegetable 


Why  Digestibility  Varies  125 

fats  aud  oils  are  quite  completely  emulsified  and  ab- 
sorbed. 

The  foregoing  statements  make  it  plain  that  when 
the  general  composition  of  a  feeding  stuff  is  known  it 
is  possible  to  predict  with  a  good  degree  of  certainty 
whether  its  rate  of  digestibility  is  high  or  low.  The 
larger  the  proportion  of  starch  and  sugar  and  the  smaller 
the  percentage  of  gums  and  fiber,  the  more  complete 
will  be  the  solution.  We  see  this  illustrated  in  the  ex- 
treme by  the  difference  in  digestibility  of  corn  meal  and 
of  wheat  straw. 


CHAPTER   IX 

CONDITIONS  INFLUENCING   DIGESTION 

The  chemical  changes  and  other  phenomena  consti- 
tuting digestion,  which  have  been  described  as  occurring 
in  the  alimentary  canal,  are  practically  outside  the  con- 
trol of  the  one  who  feeds  the  animals.  They  proceed 
in  accordance  with  fixed  chemical  and  physiological 
laws.  It  is,  however,  within  the  power  of  the  feeder 
to  so  manipulate  the  food  or  vary  the  conditions  under 
which  it  is  fed  that  the  extent  or  completeness  of  diges- 
tion is  modified,  and  this  must  be  regarded  as  an  im- 
portant matter  when  we  remember  that  only  the  digested 
food  is  useful. 

PALATABLENESS 

It  is  entirely  reasonable  to  believe  that  a  thorough 
relish  for  food  is  conducive  to  good  digestion.  The 
secretion  of  the  digestive  juices  is  not  a  mechanical 
process,  but  is  under  the  control  of  the  nervous  system. 
With  man,  at  least,  the  enjoyment  of  eating,  even  its 
anticipation,  stimulates  the  secretory  power  of  the  sal- 
ivary glands  and  those  in  the  mucus  lining  of  the 
stomach,  and  it  is  evident  that  this  holds  true  with 
animals.  Palatableness  is,  therefore,  an  important  fac- 
tor in   successful   feeding,  for  it   tends   to   promote  a 

(126) 


Influence   of  Palatahleness,   Quantity  127 

state  of  vigorous  activity  on  the  part  of  the  digestive 
organs.  The  experienced  feeder  knows  well  the  value 
of  stimulating  the  appetite  of  his  animals  by  means  of 
attractive  mixtures.  An  agreeable  flavor  or  taste  adds 
nothing  to  the  energy  or  building  capacity  of  a  food, 
but  it  does  tend  to  secure  a  thorough  appropriation  of 
the  nutrients  which  enter  the  alimentary  canal.  With- 
out doubt,  the  success  of  one  feeder  as  compared  with 
the  failure  of  another  may  sometimes  be  due,  in  part, 
to  a  superior  manner  of  presenting  a  ration  to  the 
animal's  attention  and  to  manipulations  that  add  to 
the  agreeableness  of  its  flavors. 

INFLUENCE    OF    QUANTITY    OF    RATION 

Early  experiments  by  Wolff,  in  which  he  fed  larger 
and  smaller  rations  of  the  same  fodder  to  the  same 
animals,  have  been  made  the  authority  for  the  state- 
ment that  a  full  ration  is  as  completely  digested  as  a 
scanty  one,  provided  the  former  does  not  pass  the  nor- 
mal capacity  of  the  animal.  It  must  be  said,  however, 
that  the  testimony  concerning  this  point  is  not  unani- 
mous. Since  Wolff's  experiments,  Weiske,  in  feeding 
oats  to  rabbits,  found  the  digestibility  to  be  inversely 
as  the  quantity  of  food  taken.  In  experiments  with 
oxen,  by  G.  Klihn,  at  Mockern,  when  the  grain  ra- 
tion was  doubled  the  digestibility  of  the  malt  sprouts 
used  was  decreased  about  nine  per  cent.  Results  at 
the  New  York  Experiment  Station  from  feeding  full 
and  half  rations  to  four  sheep  showed  uniformly  higher 
digestion  coefficients  with  the  smaller  ration,  the  differ- 


128  The  Feeding  of  Animals 

ences  being  too  large  and  too  constant  to  be  considered 
accidental.  Other  experiments  give  varying  and  con- 
flicting figures.  If  we  assume  that  the  constituents  of 
feeding  stuffs  have  a  certain  fixed  solubility  in  the  di- 
gestive fluids,  then  within  reasonable  limits  the  amount 
of  food  should  have  no  effect  upon  the  proportions  of 
nutrients  digested,  but  such  an  assumption  cannot  safely 
be  made. 

Doubtless  no  single  statement  concerning  this  point 
Avill  be  found  applicable  to  all  animals  and  all  rations. 
Certainly,  overfeeding  may  lessen  the  extent  of  solution 
and  is  never  wise,  while  nnder- feeding  for  the  sake  of 
securing  a  maximum  digestibility  would  not  be  good 
practice.  It  is  reasonable  to  suppose,  however,  that 
the  relation  in  quantity  between  the  enzyms  and  the 
food  compounds  has  an  influence,  at  least,  upon  the 
rapidity  of  digestion  ;  and  indeed  investigations  by 
Stone  very  strongly  point  to  such  a  conclusion,  for  he 
found  that  the  rate  of  ferment  action  was  proportional 
to  the  concentration  of  the  ferment  solution. 

EFFECT  OF  DRYING  FODDERS 

At  one  time  the  belief  became  very  firmly  fixed  in 
the  public  mind  that  curing  a  fodder  causes  a  material 
decrease  in  its  digestibility.  Because  this  drying  is 
often  carried  on  under  conditions  that  admit  of  de- 
structive fermentations  or  of  a  loss  of  the  finer  parts 
of  the  plant,  this  view  is  probably  correct  for  partic- 
ular cases,  but  if  it  is  accomplished  promptly  and  in 
a  way  that  precludes  fermentation  or  loss  of  leaves  it  is- 


Treatment    of  Fodders  129 

doubtful  if  curing  has  any  material  effect  upon  digesti- 
bility. 

The  point  has  been  the  object  of  six  American  di- 
gestion experiments,  Hungarian,  timothy,  pasture  grass, 
corn  fodder,  crimson  clover  and  winter  vetch  being  the 
experimental  foods.  With  four  of  these  slight,  but  un- 
important, differences  were  observed  in  favor  of  the 
dried  material,  while  the  reverse  was  decidedly  true  of 
the  crimson  clover  and  the  corn  fodder.  German  ex- 
periments show  in  a  majority  of  cases  greater  digesti- 
bility for  the  green  fodders.  It  seems  probable  that 
in  general  practice,  because  of  greater  or  less  unavoid- 
a-ble  fermentation  and  a  loss  of  the  finer  parts  of  the 
plant,  dried  fodders  have  a  somewhat  lower  rate  of 
digestibility  than  the  original  green  material,  a  fact 
not  due  directly  to  drying,  but  to  a  decrease,  either 
of  the  more  soluble  compounds  or  of  the  tender  tissues. 

INFLUENCE    OF    THE    CONDITIONS    AND    METHODS    OF 
PRESERVING    FODDERS 

In  comparing  the  conditions  and  methods  of  pre- 
serving fodders  in  their  relation  to  digestibility,  we  may 
safely  rest  upon  the  general  statement  that  when,  for 
any  cause,  leaching  occurs  or  fermentations  set  in,  di- 
gestibility is  depressed.  The  explanation  of  this  state- 
ment is  that  those  compounds  of  the  plant  which  are 
entirely  soluble  in  the  digestive  fluids,  notably  the 
sugars,  are  the  ones  wholly  or  partially  removed  or 
destroyed  by  leaching  or  fermentations,  while  the  more 
insoluble  bodies  remain  unaffected.  When,  therefore, 
hay  is  cured  under  adverse  conditions,  such  as  long -con- 


130  The  Feeding  of  Animals 

tinned  rain,  digestibility  is  decreased,  and  the  same  effect 
is  inevitable  from  the  changes  which  occur  in  a  ferment- 
ing mass,  such  as  a  mow  of  wet  haj%  a  pile  of  corn- 
stalks or  the  contents  of  a  silo.  Experimental  evidence 
of  the  truth  of  these  statements  is  not  wanting.  Ger- 
man digestion  trials  with  alfalfa  and  esparsette,  green, 
carefully  dried,  cured  in  the  ordinary  way,  fermented 
after  partial  drying  and  as  silage,  show  a  gradually 
decreasing  digestibility  from  the  first  condition  to  the 
last.  A  single  American  experiment,  comparing  the 
same  fodder  both  green  and  as  silage,  gives  testimony  in 
the  same  direction.  On  the  other  hand,  field- cured  corn 
fodder,  according  to  nine  out  of  eleven  American  ex- 
periments, is  considerably  less  digestible  than  silage 
coming  from  the  same  source.  Here  it  is  largely  a 
question  of  the  relative  loss  by  fermentation  in  the  two 
cases,  and  it  is  t.o  be  expected  that  the  outcome  would 
not  be  wholly  one  way. 

INFLUENCE    OF    THE    STAGE    OF    GROWTH   OF   THE    PLANT 

Another  generalization,  which  certainly  must  hold 
good  with  reference  to  the  digestibility  of  fodder  plants, 
is  that  any  conditions  of  development  which  favor  a 
relatively  large  proportion  of  the  more  soluble  carbo- 
hydrates; viz.,  starches  and  sugars,  and  secure  a  min- 
imum of  gums  and  fiber,  promote  a  high  rate  of  diges- 
tibility, and  reverse  conditions  produce  the  opposite 
result.  It  is  well  known  that,  in  general,  as  the  meadow 
grasses  mature  the  relative  proportion  of  fiber  increases 
and  the  tissue  becomes  harder  and  more  resisting.    Nu- 


stage    of   Gr'owth,    Preparation  131 

merous  American  and  European  digestion  trials  unite  in 
testifying  almost  unanimously  to  a  gradually  diminished 
digestibilit}'  as  the  meadow  grasses  increase  in  age. 
The  maturing  of  maize  seems  to  produce  quite  the  con- 
trary effect.  The  testimony  of  experiments  conducted 
at  the  Connecticut,  Maine  and  Pennsylvania  Experiment 
Stations  justifies  the  statement  that  the  corn  plant,  cut 
when  the  ears  are  full  grown,  furnishes  not  only  a  larger 
amount  of  digestible  material,  but  a  larger  relative  pro- 
portion than  when  cut  before  the  ears  have  formed; 
and  this  is  strictly  in  harmony  with  our  general  prin- 
ciple; for  the  mature  plant,  on  account  of  the  storage 
of  starch  in  the  kernels,  has  by  far  a  larger  proportion 
of  the  more  digestible  carbohydrates. 

INFLUENCE    OF    METHODS    OF    PREPARATION    OF    FOOD 

Much  labor  and  expense  have  been  expended  by 
farmers  in  giving  to  feeding  stuffs  special  treatment, 
such  as  wetting,  steaming,  cooking  and  fermenting,  in 
order  to  secure  a  supposed  increase  in  nutritive  value, 
an  increase  which  must  come  chiefly,  if  at  all,  from  a 
more  complete  digestion.  It  is  plainly  noticeable  that 
these  methods  of  feeding  have  lost  in  prevalence  rather 
than  gained.  Practice  does  not  seem  to  have  perma- 
nently ratified  them,  and,  so  far  as  digestibility  is 
concerned,  this  outcome  is  in  accordance  with  the  re- 
sults of  scientific  demonstration.  The  conclusions  of 
German  experimenters  have  been  that  these  special 
treatments  have  no  favorable  influence,  their  effect 
being  either  imperceptible  or  unfavorable. 


132  Tlie  Feeding  of  Animals 

It  should  occasion  no  surprise  that  the  mere  wetting 
of  a  food  is  without  influence  upon  its  solubility  in  the 
digestive  juices,  because  it  becomes  thoroughly  mois- 
tened during  mastication  and  in  the  stomach.  It  is 
not  rational  to  expect  that  previous  wetting  would  have 
the  slightest  effect  unless  it  induced  more  complete 
mastication,  which  certainly  would  not  be  the  case  with 
ground  grains.  The  extensive  trials  by  Kiihn  and 
others  with  a  hay  and  bran  ration,  the  bran  being  fed 
in  several  conditions,  such  as  dry,  wet,  moistened  some 
hours  before  feeding,  treated  with  boiling  water  and 
fermented,  gave  results  adverse  to  all  of  the  special 
methods  of  preparation  as  either  useless  or  harmful, 
and  no  testimony  so  thorough  and  convincing  has  been 
furnished  on  the  other  side. 

German  and  American  experiments  unite  in  con- 
demning the  cooking  of  foods  already  palatable,  because 
this  .causes  a  marked  depression  of  the  digestibility  of 
the  protein,  with  no  compensating  advantages.  Diges- 
tion trials  with  cooked  or  steamed  hays,  silage,  lupine 
seed,  cornmeal  and  wheat  bran,  and  roasted  cotton 
seed,  uniformly  show  their  protein  to  be  notably  less 
digestible  than  that  in  the  original  materials,  a  fact 
which  may  explain  the  lessened  productive  value  of 
cooked  grains  which  has  been  observed  in  certain  ex- 
periments. It  must  be  conceded,  of  course,  that 
when  cooking  feeding  stuffs  by  steaming  or  otherwise 
renders  them  more  palatable,  and  thereby  makes  pos- 
sible the  consumption  of  material  otherwise  wasted, 
the  influence  upon  digestibility  is  a  minor  consid- 
eration. 


Influence  of  Grinding  and  of  Salt  133 

INFLUENCE    OF    GRINDING 

Few  points  are  more  frequently  questioned  than  the 
profitableness  of  grinding  grain.  There  seem  to  be 
onh'  two  ways  in  which  such  preparation  can  enhance 
the  nutritive  value  of  a  feeding  stuff;  viz.,  by  dimin- 
ishing the  energy  needed  for  the  digestive  processes 
and  by  increasing  the  digestibility.  While  only  about 
a  half-dozen  experiments  bearing  upon  the  digestion 
side  of  this  question  are  on  record,  their  evidence  is 
quite  emphatic.  In  three  trials  with  horses,  with  both 
corn  and  oats,  grinding  caused  an  increase  of  digesti- 
bility varying  from  3.3  to  14  per  cent.  A  single 
experiment  with  maize  kernels  gave  a  greater  diges- 
tibility of  about  7  per  cent  from  grinding,  and  with 
wheat,  in  one  trial,  the  increase  was  10  per  cent.  In 
one  test  of  oats  with  sheep,  the  unground  kernels  were 
as  completely  utilized  as  the  ground.  It  is  reasonable 
to  expect  that  with  ruminants  the  danger  of  imperfect 
mastication  is  less  than  with  horses  and  swine,  although 
whole  kernels  of  grain  are  often  seen  in  the  feces  of 
bovines.  The  profitableness  of  grinding  grain  turns,  in 
part  at  least,  upon  the  relation  of  the  cost  of  grinding  to 
the  loss  of  nutritive  material  from  not  grinding.  If  the 
miller's  toll  amounts  to  one -tenth  the  value  of  the  grain 
the  economy  of  grinding  it  may  be  doubtful,  especially 
with  ruminants. 

EFFECT    OF    COMMON    SALT 

It  is  the  custom  of  many  feeders  to  allow  their  ani- 
mals an  unlimited  supply  of  salt,  and  others  furnish  it 


134  The  Feeding  of  Animals 

in  definite  and  regular  quantities.  The  belief  prevails 
more  or  less  widely  that  an  abundant  consumption  of 
salt  is  beneficial.  If  this  is  true,  the  advantage  arises 
for  other  reasons  than  an  increased  digestibilit.y.  The 
verdict  from  earlier  experiments  by  Grouven,  Hofmeis- 
ter  and  Weiske  that  the  addition  of  salt  to  the  ration 
does  not  increase  the  digestibility  has  been  confirmed 
by  more  recent  tests  b}^  Wolff.  Indeed,  if  we  give  to 
the  data  collected  a  literal  and  perfectly  justifiable  in- 
terpretation, salt  diminished  rather  than  raised  the 
proportion  of  digestible  nutrients. 


INFLUENCE    OP    FREQUENCY    OF    FEEDING    AND    WATERING 
ANIMALS 

Few  experiments  relative  to  this  point  are  on  rec- 
ord. One  by  Weiske  and  others,  relative  to  frequency 
of  feeding,  and  another  by  Gabriel  and  Weiske,  in 
which  the  effects  of  the  time  of  watering  and  of  the 
amount  of  water  were  tested,  give  no  indication  that 
the  completeness  of  digestion  is  materially  affected  by 
variations  in  these  details  of  practice.  It  seems  proba- 
ble that  the  nutritive  importance  of  these  minor  points 
in  managing  animals  has  been  much  overestimated  by 
some,  especially  as  affecting  the  utilization  of  the  food. 

INFLUENCE     OF     CERTAIN    OTHER    CONDITIONS 

It  is  well  known  that  the  composition  of  fodder 
crops  grown  on  tlie  same  soil  may  vary  somewhat  from 
year  to  year  according  as  the  season  is  wet  or  dry,  cold 


Combination  of  Niitrients  135 

or  warm.  Such  variations  may  influence  digestibility, 
though  no  actual  demonstration  of  this  fact  appears  to 
be  on  record.  The  question  is  often  asked  whether  the 
storage  of  hay  for  a  long  period  affects  its  nutritive 
value.  The  data  from  four  series  of  experiments 
touching  on  this  point  indicate  that  there  is  a  per- 
ceptible, though  not  marked,  decrease  in  digestibility  of 
hay  during  long -continued  storage. 

INFLUENCE     OF    THE    COMBINATION     OF    FOOD    NUTRIENTS 

Among  the  apparently  important  and  freely  ex- 
ploited conclusions  drawn  from  investigations  in  ani- 
mal nutrition  is  the  statement  that  the  'digestibility  of 
food  is  influenced  to  a  marked  degree  by  the  relative 
proportions  of  the  several  classes  of  nutrients.  It  is 
taught  that  if  more  than  a  certain  percentage  of  starch 
and  sugar,  or  of  feeding  stuffs  rich  in  carbohydrates, 
like  potatoes  or  roots,  is  added  to  a  basal  ration,  the 
digestibility  of  the  latter  is  decreased,  the  protein  and 
fiber  being  especially  affected.  The  conclusions,  as 
stated  by  Dietrich  and  Konig,  on  the  basis  of  a  criti- 
cal study  of  the  data  involved  are  that  if  pure  carbo- 
hydrates are  used  to  the  extent  of  more  than  10  per 
cent  of  the  dry  substance  of  a  basal  ration,  or  if  pota- 
toes and  roots  are  fed  equivalent  in  dry  matter  to 
more  than  15  per  cent,  a  depression  of  digestibility 
occurs,  which  increases  with  the  amount  of  carbo- 
hydrate material  added.  A  modifying  conclusion  is, 
that  if  the  addition  of  the  carbohydrate  material  is 
accompanied  by  correspondingly  more  protein,  the  de- 


136  The  Feeding  of  Animals 

pression  of  the  digestion  coefficients  is  much  lessened 
or  does  not  occur.  Many  data  are  cited  in  support  of 
these  generalizations  which  are  worthy  of  careful  con- 
sideration. 

It  is  not  unreasonable  to  suppose  that  the  relative 
quantity  in  a  ration  of  the  several  classes  of  nutrients 
may  have  an  influence  upon  the  digestive  processes, 
and  we  should  accept  the  verdict  of  previous  observa- 
tions in  so  far  as  they  will  bear  critical  discussion  and 
further  investigation.  It  should  be  said  in  the  first 
place,  by  way  of  comment,  that  the  carbohydrate  ma- 
terial in  the  experiments  cited  has  usuall}^  been  fed  in 
addition  to  a  basal  ration,  thus  increasing  the  amount 
of  food  consumed,  and,  as  we  have  seen,  this  may  have 
an  influence  upon  the  proportion  of  total  dry  matter 
digested.  In  this  particular,  the  experiments  have  not 
been  logical. 

In  the  second  place,  in  these  experiments,  no  allow- 
ance has  been  made  for  the  metabolic  nitrogen  in  the 
feces,  i.  e.,  that  not  belonging  to  the  true  undigested 
residue.  As  this  appears  to  be  independent  of  the 
amount  of  protein  fed  and  stands  more  nearly  in  rela- 
tion to  the  total  digested  nutrients,  it  follows  that  the 
smaller  the  proportion  of  protein  in  the  digested  food, 
the  larger  the  error  caused  by  the  waste  nitrogen 
products.  A  careful  study  of  this  point  in  the  light  of 
more  recent  knowledge  might  modify  the  conclusion, 
reached  as  to  the  depression  of  protein  digestion 
through  feeding  starch  or  starchy  foods.  In  all  or 
nearly  all  the  experiments  where  this  effect  is  appar- 
ently shown    the    digestible    dry  matter   of  the   ration 


Digestion  —  Influence  of  Animal  137 

was  largely  increased  and  the  protein  remained  con- 
stant or  was  diminished.  The  depression  of  the  di- 
gestibility of  the  crude  fiber  is  not  easily  explained 
on  any  other  ground  than  that  of  the  influence  of  the 
greater  proportion  of  starch. 

What  is  claimed  as  the  effect  of  a  dispropor- 
tionate addition  to  the  supply  of  carbohydrates  does 
not  appear  to  be  true  of  a  similar  increase  in  the 
ration  of  fat  and  easily  digested  protein.  Several  ex- 
periments in  which  oils  and  albuminoids  have  been 
added  freely  to  a  basal  ration  did  not  indicate  that 
such  addition  had  any  material  effect  upon  digesti- 
bility. 

CONDITIONS   PERTAINING   TO   THE   ANIMAL:    SPECIES, 
BREED,  AGE,  AND   INDIVIDUALITY 

The  conclusion  reached  by  the  early  experimenters 
in  the  field  of  animal  nutrition  that  the  digestive  effi- 
ciency of  the  several  species  of  ruminants  was  prac- 
tically uniform,  has  not  been  set  aside  by  more  recent 
observations.  The  number  of  experiments  upon  which 
this  conclusion  was  based  was  large,  and  their  verdict 
is  not  likely  to  be  reversed  by  observations  less  ex- 
tensive or  less  complete. 

The  following  coefficients  were  obtained  from  Ger- 
man trials  with  meadow  hay: 

Dry  substance  digested  from  meadow  liny  {per  cent) 

Samples  Best  Medium  Poor 

Sheep 42  67     Gl  55 

Oxen 10  67     64  56 

Horse 18  58     50  46 


138  The  Feeding  of  Animals 

Nine  American  experiments  have  been  the  means  of 
studying  results  with  large  and  small  ruminants,  steers 
being  compared  with  sheep  and  cows  with  goats.  In 
five  cases,  the  large  animal  digested  from  5  to  14  per 
cent  the  more,  in  three  cases  the  excess  for  the  small 
animal  varied  between  7  and  17  per  cent,  and  in  one 
case  there  was  little  difference.  The  general  effect  of 
such  conflicting  results  is  to  confirm  the  older  and 
more  numerous  observations. 

The  horse  and  ruminants  differ  in  digestive  ca- 
pacity to  a  marked  extent.  The  comparisons  which 
have  been  made  show  a  uniformlj^  lower  digestive  effi- 
ciency for  coarse  fodders  on  the  part  of  the  former. 
It  appears  that  because  of  less  perfect  mastication,  or 
for  some  other  reason,  the  horse  dissolves  much  less 
of  the  crude  fiber  than  the  steer  or  sheep,  and  the 
effect  of  this  is  prominent  with  hays  and  other  fibrous 
materials.  With  the  grains,  ruminant  and  equine  diges- 
tion are  not  greatly  unlike,  eight  samples  of  oats  with 
sheep  and  twenty-four  with  the  horse  showing  almost 
identical  digestion  of  the  dry  matter.  With  maize  the 
case  is  the  same.  In  experiments  with  beans,  the  ad- 
vantage was  slightly  with  the  ruminant.  So  far  as 
we  are  able  to  judge,  swine  digest  concentrated  food 
about  as  do  ruminants  and  the  horse.  How  this  is 
in  the  case  of  the  fodders  Ave  do  not  know  fully, 
but  it  is  proven  that  the  swine  digest  crude  fiber  quite 
freely. 

Past  experiments  have  not  revealed  any  influence  of 
breed  upon  digestive  capacity.  There  is  no  reason  for 
supposing  that  Shorthorn  cattle,  Southdown  sheep  and 


Digestibility — How  Determined  139 

Chester  White  pigs  would  digest  rations  differently  from 
Jerseys,  Merinoes  and  Yorkshires. 

Young  animals  seem  to  digest  high  quality  coarse 
foods  and  grains  as  efficiently  as  older  ones  of  the  same 
species,  which  is  probabh'  contrary  to  the  popular  belief. 
There  is  doubtless  a  variation  in  the  digestive  power  of 
individual  animals,  but  the  data  so  far  collected  do  not 
show  this  with  any  degree  of  definiteness.  In  those  in- 
stances where  the  same  four  or  more  steers  or  sheep 
have  been  used  in  determining  the  digestibility  of  sev- 
eral feeding  stuffs  the  highest  coefficients  were  obtained 
sometimes  with  one  animal  and  sometimes  with  another. 

DETERMINATION   OF   DIGESTIBILITY 

If  we  accept  as  the  undigested  food  the  dry  matter 
of  the  solid  excrement,  which  is  practically  in  accor- 
dance with  the  fact,  we  have  only  to  subtract  this  fecal 
residue  from  the  dry  matter  of  the  ingested  food  in  order 
to  ascertain  the  amount  and  proportion  digested.  All 
digestion  experiments  have  proceeded  on  this  basis. 
Animals  have  been  fed  at  regular  intervals  a  uniform 
quantity  of  carefully  analyzed  food  and  the  feces  have 
been  collected,  weighed  and  analj-zed.  From  the  data 
thus  obtained,  the  digestion  coefficients  have  been  cal- 
culated. The  method  and  the  mathematics  of  such 
experiments  are  so  simple  that  correct  results  seem  very 
easy  to  obtain  and  they  do  possess  an  accuracy  suffi- 
cientlj"  approximate  to  truth  to  render  them  useful  in 
practice.  As  digestion  trials  are  usually  conducted,  the 
coefficients  of  digestibility  obtained  for  the  dry  matter 


140  The  Feeding  of  Animals 

and  total  organic  matter  represent,  we  have  reason  to 
believe,  very  nearly  the  actual  digestible  matter  in  the 
particular  material  studied.  The  proportions  secured 
for  particular  classes  of  nutrients  may  be  less  accurate, 
for  reasons  that  will  appear.  We  cannot  be  sure,  either, 
that  the  digestibility  of  one  hay  applies  to  another 
produced  and  cured  under  totally  different  conditions. 
The  truth  of  this  latter  statement  is  clearly  seen  in  the 
effect  of  the  various  factors  upon  digestibility. 

The  inaccuracies  of  digestion  coefficients  are  chiefly 
in  those  for  protein  and  fats.  Let  us  see  how  and  why 
this  is.  The  errors  in  the  figures  for  protein  are  caused 
by  the  presence  in  the  feces  of  nitrogen  compounds 
which  are  not  a  part  of  the  undigested  food  protein. 
These  are  waste  compounds  which  are  residues  from  the 
bile  and  other  digestive  juices,  epithelial  cells  and  mucus 
which  are  carried  along  from  the  walls  of  the  intestines 
during  the  passage  of  the  food.  Their  quantity  seems 
not  to  be  proportional  to  the  protein  fed,  but  appears 
to  be  influenced  more  or  less  by  the  amount  of  food 
digested.  Their  source  is  the  "wear  and  tear"  of  the 
digestive  apparatus.  It  follows  then  that  the  less  pro- 
tein there  is  in  a  ration,  the  larger  the  percentage  error 
caused  by  these  metabolic  products.  In  certain  experi- 
ments with  oat  straw,  the  fecal  nitrogen  has  been  more 
than  that  of  the  food,  although  without  question  much 
of  the  straw  protein  was  digested.  It  has  been  found, 
using  the  best  methods  known  for  extracting  these  waste 
products,  that  they  cause  a  much  larger  error  for  the 
protein  of  the  straws  than  for  that  of  the  legume  hays. 
It   is  probably  safe  to  affirm  that  at  least  ten  should 


Digestibility — How  Determined  141 

be  added  to  the  coefficients  of  digestibility  of  the  pro- 
tein of  coarse  fodders  as  usually  given  in  the  tables  that 
have  been  compiled. 

Errors  are  caused  in  determination  of  the  digesti- 
bility of  fat  in  much  the  same  way.  Certain  of  the  bile 
residues  in  the  solid  excrement  are  soluble  in  the  ether 
which  is  used  to  extract  the  fats,  and  consequently  the 
undigested  fat  appears  to  be  larger  than  it  really  is. 


CHAPTER   X 

THE  DISTRIBUTION  AND  USE   OF  THE  DIGESTED  FOOD 

The  digested  food,  after  absorption,  all  passes  into 
the  blood,  either  directly  or  indirectly,  and  mixes  with 
it.  The  materials  which  are  to  serve  the  purposes  of 
nutrition  are  now  taken  up  bj^  a  stream  of  liquid  that  is 
in  constant  motion  throughout  the  minutest  divisions 
of  every  part  of  the  animal.  Flowing  in  regular  chan- 
nels the  blood  reaches  not  only  the  bones  and  muscular 
tissues,  but  it  passes  through  several  special  organs  and 
glands  where  the  nutrients  it  is  carrying  and  certain 
of  its  own  constituents  meet  with  profound  changes. 
It  is  here  that  we  discover  the  manner  in  which  food 
is  applied  to  use  and  what  are  some  of  the  transforma- 
tions which  the  proteids,  carbohydrates  and  fats  under- 
go in  performing  their  functions. 

In  order  to  foUoAV  intelligently  this  most  interesting 
phase  of  nutrition,  we  must  know  something  of  the 
blood  and  of  the  organs  —  the  lungs,  liver  and  kidnej'S 
—  through  which  it  passes. 

THE     BLOOD 

The  blood,  when  in  a  fresh  state,  is  apparently 
colored   and   opaque,  but   if   a   minute   portion   is  ex- 

(142) 


Blood  and  its  Ftinctions  143 

amined  with  a  microscope,  it  is  seen  to  be  a  compar- 
atively clear  liquid  in  which  float  numerous  reddish, 
disk  -  like  bodies.  These  bodies,  which  are  known 
as  corpuscles,  give  to  the  blood  its  bright  red  color. 
The  liquid  in  which  they  are  suspended  is  called  the 
plasma. 

The  corpuscles  are  not  mere  masses  of  unformed 
matter,  but  they  are  minute  bodies  having  a  definite 
form  and  structure.  They  make  up  from  35  to  40  per 
cent  of  the  blood,  and  contain  over  30  per  cent  of  dry 
matter.  This  dry  matter  consists  mostly  of  haemo- 
globin, a  compound  that  is  peculiar  to  the  blood  and 
equips  it  for  one  of  its  most  important  offices.  Haemo- 
globin, as  before  stated,  is  made  up  of  a  proteid  (globin) 
and  a  coloring  matter  (hfematin),  in  the  latter  of  which 
is  combined  a  definite  proportion  of  iron.  The  peculiar 
property  of  this  compound,  which  renders  it  so  useful 
a  constituent  of  the  blood,  is  its  power  of  taking  up 
oxygen  and  holding  it  in  a  loose  combination  until  it 
is  needed  for  use.  When  thus  charged,  it  is  known 
as  oxyhaemoglobin.  Because  of  this  function  of  their 
most  prominent  constituent,  blood  corpuscles  become 
the  carriers  of  oxygen  to  all  parts  of  the  body.  There 
are  reasons  for  believing  that  they  are  also  chiefly  con- 
cerned in  gathering  up  one  of  the  waste  products  of 
the  nutritive  changes,  viz.,  carbon  dioxid,  and  convey- 
ing it  to  the  points  where  it  may  be  thrown  off  from 
the  body. 

The  plasma  is  about  nine-tenths  water,  so  that  it 
easily  holds  in  solution  whatever  soluble  nutrients  are 
discharged  into  it  from  the  alimentary  canal.     Among 


144  The  Feeding  of  Animals 

its  constituents  are  found  members  of  all  the  classes 
of  compounds  that  are  important  in  this  connection, — 
ash,  protein,  carbohj'drates  and  fats.  The  proportion 
of  ash  is  about  1  per  cent,  three-fourths  of  it  being 
common  salt,  and  the  remainder  consisting  of  phos- 
phoric acid,  lime  and  other  important  mineral  com- 
pounds. The  solid  matter  of  the  plasma  is  rich  in 
albuminoids,  including  the  fibrinogen  which  is  the 
mother  substance  of  fibrin  and  several  albumins  and 
globulins.  These  proteids  make  up  about  80  per 
cent  of  the  total  dry  substance  of  plasma.  Sugar  and 
fats  are  also  present,  their  proportions  varying  with 
the  extent  to  which  they  are  being  absorbed  from  the 
digestion  of  food.  It  is  evident  that  the  blood  is 
charged  with  those  materials  which  we  recognize  as 
necessary  to  the  construction  and  maintenance  of  the 
animal  body. 

THE    HEART 

In  quantity,  the  blood  is  from  3  to  4  per  cent  of 
the  total  weight  of  the  live  animal.  It  is  contained  in 
the  heart  and  in  two  sets  of  vessels,  one  set  called  the 
arteries  leading  from  the  heart  by  various  ramifications 
to  all  parts  of  the  body,  and  the  other  set  called  the 
veins,  leading  from  all  parts  of  the  body  back  to  the 
heart.  Through  these  vessels  the  blood  is  moving  in 
a  constant  stream,  which  we  call  the  circulation.  It 
does  not  move  of  itself,  but  is  forced  along  by  a  very 
powerful  pump,  the  heart.  This  is  a  highly  muscular 
organ  divided  into  four  chambers,  which  are  separated 
by  valves  and   partitions,  the  two  upper  chambers  be- 


Worl'  of  tJie   Heart  145 

ing  called  the  right  and  left  auricles,  and  the  two 
lower  the  right  and  left  ventricles.  The  right  auricle 
is  above  the  right  ventricle  and  is  separated  from  it 
b}^  a  valve,  and  the  same  is  true  of  the  left  auricle 
and  ventricle.  Out  of  the  left  ventricle  the  blood  is 
pumped  into  the  arteries  and  after  reaching  the  arte- 
rial capillaries  throughout  the  entire  body,  it  passes 
from  these  into  the  smallest  divisions  of  the  veins  and 
comes  back  to  the  heart  along  the  venous  system,  en- 
tering the  right  auricle.  It  is  then  carried  to  the 
lungs  by  way  of  the  right  ventricle  and  is  returned  to 
the  left  auricle  to  be  sent  to  the  left  ventricle,  and 
from  there  to  again  start  on  its  journey  through  the 
body.  The  principal  facts  pertaining  to  the  blood  and 
its  circulation  have  been  reviewed  in  this  simple  man- 
ner as  an  aid  to  the  discussing  of  other  considerations 
somewhat  pertinent  to  our  subject. 

The  nutrients,  as  prepared  for  use  by  digestion, 
enter  the  blood  on  its  return  flow  to  the  heart,  com- 
ing into  the  venous  cavity  by  w^ay  of  the  hepatic 
(liver)  vein  and  the  thoracic  duct  as  previously  de- 
scribed. When,  therefore,  the  right  side  of  the  heart 
is  reached,  a  new  accession  of  food  material  is  on  its 
way  to  sustain  the  various  functions  of  nutrition. 

We  are  more  interested  in  the  object  of  blood  cir- 
culation than  we  are  in  its  mechanism.  Somehow  the 
digested  food  disappears  into  these  constantly  moving 
blood  currents,  and  the  only  evidence  of  its  effect 
which  comes  to  us  from  ordinary  observation  is  the 
warmth,  motion  and  perhaps  growth  of  the  animal  that 
is  nourished. 


146  The  Feeding  of  Animals 


THE    LUNGS 

The  first  point  where  important  changes  occur  is  the 
lungs.  Here  the  blood  loses  the  purplish  hue  which 
it  always  has  after  being  used  in  the  body  tissues 
and  takes  on  a  bright  scarlet,  a  phenomenon  that  is 
more  easily  understood  when  we  understand  the  lung 
structure. 

Breathing  is  a  matter  of  common  experience.  We 
all  know  how  air  is  drawn  into  the  lungs  at  regular 
intervals,  an  equivalent  quantity  being  as  regularly 
forced  out.  The  mechanism  of  respiration  (breathing) 
we  will  not  discuss  at  length.  It  will  aid  us,  however, 
if  we  know  that  the  passage  which  the  air  follows  to  and 
from  the  lungs,  the  trachea  (windpipe),  divides  into  two 
branches,  one  to  each  lung,  and  these  divide  and  sub- 
divide until  they  branch  into  numerous  fine  tubes. 
Each  of  these  tubes  ends  in  an  elongated  dilation  which 
is  made  up  of  air  cells  opening  into  a  common  cavitj-. 
These  cells  are  so  numerous  in  the  lung  tissues  that  only 
a  very  thin  wall  separates  adjoining  ones,  and  in  this 
wall  are  carried  the  capillaries  or  fine  divisions  of  the 
blood-vessels  leading  from  the  heart.  This  arrange- 
ment permits  the  blood  to  take  up  oxygen  as  it  flows 
along  and  transfer  certain  wastes  into  the  lung  cavities, 
and  thus  be  made  ready  to  go  back  to  the  body  carry- 
ing a  joint  load  of  digested  food  and  oxygen.  Of  cours6 
the  air  that  passes  out  of  the  lungs  is  less  rich  in 
oxygen  than  when  it  was  taken  in,  and  there  have 
been  added  to  it  certain  materials  which  we  will  notice 
later. 


Changes  of  Food  in  the   Tissues  147 


THE   USE   OF   FOOD 

The  revivified  blood  now  passes  to  all  parts  of  the 
body  and  is  brought  into  the  most  intimate  relation  with 
the  minutest  portion  of  every  tissue.  Several  things 
happen  in  the  course  of  time. 

In  the  first  place,  the  new  supply  of  nutritive  sub- 
stances is  used  by  the  living  cells  in  a  way  we  do  not 
wholly  understand  to  rebuild  worn-out  tissue  and  to 
form  new  growth.  With  the  young  animal,  much 
material  is  appropriated  in  the  latter  way.  In  the  case 
of  the  milch  cow,  there  is  furnished  to  the  ndder  the 
nutrients  out  of  which  the  milk  is  formed  through 
the  special  activities  of  that  gland. 

Moreover,  it  is  in  the  tissues  that  the  oxygen  which 
was  taken  up  in  the  lungs  is  used  to  slowly  burn  a  por- 
tion of  the  food.  This  combustion  is  believed  not  to 
take  place  by  contact  of  the  oxygen  and  food  in  the 
large  blood-vessels,  but  it  occurs  by  progressive  steps 
throughout  the  minute  divisions  of  the  muscles  and 
other  parts  of  the  whole  body.  Notwithstanding  this 
oxidation  may  be  very  gradual  and  occupy  much  time, 
its  ultimate  products  are,  for  the  most  part,  similar  to 
those  which  result  from  the  rapid  combustion  of  fuel. 
In  the  fireplace,  starch,  sugar,  cellulose,  fats  and  similar 
bodies  would  be  burned  to  carbonic  acid  and  water,  and 
this  is  what  takes  place  in  the  animal  to  the  extent 
these  nutrients  are  not  used  for  growth. 

When  the  protein  is  not  stored  as  such  but  is  broken 
up,  the  result  differs  somewhat  in  the  furnace  and  in 
the  animal  because  in  the  latter  the  oxidation  is  not 


148  The  Feeding  of  Animals 

complete.  Here  the  proteids  may  be  partially  burned 
to  carbonic  acid  and  water,  but  a  portion  of  their  sub- 
stances passes  from  the  body  principally  in  the  form  of 
urea  and  uric  acid,  which  are  the  prominent  constituents 
of  urine.  These  compounds  carry  with  them  a  certain 
proportion  of  carbon  and  hydrogen  which  in  ordinary 
fuel  combustion  would  more  fully  unite  with  oxygen. 
The  heat  production  from  protein  is  therefore  less  in 
the  animal  than  in  the  furnace. 

This  oxidation  in  the  animal  is  constant  but  not 
uniform.  It  varies  with  the  exercise  the  animal  is  tak- 
ing and  with  the  amount  of  food  that  must  be  disposed 
of.  The  quantity  of  oxygen  needed  is  therefore  vari- 
able, and  when  the  demand  for  it  is  largely  increased 
the  heart  pumps  faster,  more  blood  passes  through 
the  lungs,  the  breathing  is  more  rapid  and  the  supply 
of  oxygen  is  in  this  way  augmented. 

ELIMINATION   OF   WASTES 

The  various  waste  products  from  this  combustion 
and  from  the  breaking  up  of  the  proteids  within  the 
animal  evidently  must  be  disposed  of  in  some  manner. 
If  not  eliminated  from  the  body,  they  would  cause  re- 
sults of  a  most  serious  character,  as,  for  instance, 
when  an  accumulation  of  urea  in  the  body  produces 
uraemic  poisoning.  The  blood  therefore  not  only  carries- 
to  the  tissues  the  necessary  nutrients  and  oxygen,  but 
it  has  laid  upon  it  the  burden  of  taking  into  its  cur- 
rents the  waste  products  of  combustion  and  growth  and 
carrying  them  to  the  points  where  they  are  thrown  oif . 


Disposition  of  the    Wastes  149 

One  of  the  branches  of  the  arterial  system  of  blood- 
vessels runs  to  the  kidneys,  and,  by  repeatedly  rebranch- 
ing, traverses  all  their  substance.  The  main  function 
of  the  kidneys  is  to  secrete  the  urine,  a  liquid  in  which 
all  the  waste  nitrogen  from  the  digested  protein  finds  its 
way  out  of  the  body  in  the  form  of  urea  and  similar 
bodies.  The  blood  that  enters  them  carries  with  it  the 
urea  and  uric  acid  which  have  resulted  from  a  break- 
ing down  of  protein,  and  in  a  most  wonderful  manner 
these  compounds  are  filtered  out  so  that  they  are  not 
present  in  the  outgoing  blood.  An  excess  of  soluble 
mineral  matters  such  as  common  salt  is  also  removed 
by  the  kidneys,  as  well  as  the  bile  compounds  which 
are  absorbed  from  the  alimentary  canal. 

The  carbon  dioxid  must  in  some  way  also  be  elimi- 
nated from  the  body.  This  is  not  accomplished  to  any 
extent  until  the  blood  containing  it  reaches  the  lungs, 
where  it  is  exchanged  for  a  new  supply  of  oxygen  and 
passes  off  in  the  expired  air.  In  the  case  of  man,  the 
air  "breathed  out"  is  nearly  a  hundred  times  richer  in 
carbonic  acid  than  the  air  "breathed  in." 

Water  may  be  regarded  from  one  point  of  view  as 
a  waste,  for  it  is  produced  in  the  oxidation  of  the 
food,  and  this  passes  off  from  the  lungs  as  vapor, 
through  the  skin  as  sensible  or  insensible  perspiration, 
and  in  considerable  quantities  through  the  kidneys. 

To  summarize,  it  may  be  said  that  the  blood  is  con- 
stantly undergoing  gain  and  loss.  The  gain  comes 
from  the  food  (including  water  and  oxygen),  and  the 
loss  consists  of  urea,  carbonic  acid  and  water  given  off 
throuerh  various  channels. 


150  The  Feeding  of  Animals 

THE   LIVER 

One  part  of  the  arterial  system  of  blood-vessels 
runs  to  the  stomach  and  intestines  and  is  distributed 
over  their  walls  in  fine  divisions.  These  connect 
with  the  capillaries  of  the  portal  vein  which  leads  to 
the  liver.  During  this  passage  of  the  blood  from 
one  system  to  the  other,  it  takes  up  digested  food, 
chiefly  sugar.  Now  it  is  very  evident  that  the  quan- 
tity of  material  thus  absorbed  must  vary  greatly  at 
different  times  according  to  the  nature  and  amount  of 
food  supply  and  the  activity  of  the  digestive  processes. 
If,  therefore,  the  blood  from  the  alimentary  canal  was 
allowed  to  pass  directly  into  the  general  circulation, 
th©  supply  to  the  tissues  of  the  nutrients,  especially 
the  carbohydrates,  would  be  very  uneven.  Just  here 
comes  in  a  liver  function.  In  that  organ  there  is 
found  a  starch -like  body  known  as  glycogen,  which 
appears  in  increased  quantity  following  the  abundant 
absorption  of  sugar  from  the  intestines.  It  is  believed, 
because  of  this  and  other  facts,  that  the  liver  acts  as 
a  regulator  of  the  carbohydrate  supply  to  the  general 
tissues  of  the  body,  storing  a  temporary  excess  of  the 
sugar  in  the  form  of  glycogen  and  then  gradually 
giving  it  up  to  the  general  circulation  as  it  is  needed. 


CHAPTER  XI 

THE   FUNCTIONS   OF   THE   NUTRIENTS 

The  digestion,  absorption  and  distribution  of  food 
are  not  its  use, — they  are  the  preliminaries  necessary 
to  use.  Not  until  the  nutrients  have  been  converted 
to  available  forms  and  have  passed  into  the  blood  do 
they  in  the  slightest  degree  furnish  energy  or  building 
material  to  the  animal  organism.  We  have  followed 
to  a  certain  extent  the  chemical  changes  which  the 
digested  food  suffers,  but  no  detailed  statements  have 
been  made  as  to  the  part  taken  by  each  class  of  nutri- 
ents in  constructing  the  animal  body  and  in  maintain- 
ing its  complex  activities. 

Animals  use  food  in  two  general  ways;  viz.,  for 
constructive  purposes,  which  involve  the  building  or 
repair  of  tissue  and  the  formation  of  milk,  and  as 
fuel  for  supplying  different  forms  of  energy,  including 
heat.  The  tissues  which  are  to  be  formed  are  of  sev- 
eral kinds,  principally  the  mineral  portion  of  the  bone, 
the  nitrogenous  tissue  of  the  muscles,  tendons,  skin, 
hair,  horn  and  various  organs  and  membranes,  and  the 
deposits  of  fat  which  are  quite  generally  distributed 
throughout  the  body  substance. 

Energy  in  the  forms  in  which  it  is  used  by  the  ani- 
mal organism  may  appear  as  muscular  activity,  such  as 

(151) 


152  The  Feeding  of  Animals 

working,  walking,  breathing,  the  beating  of  the  heart, 
the  movements  of  the  stomach  and  intestines,  as  heat, 
and  as  chemical  energy  necessary  for  carrying  on  di- 
gestion and  other  metabolic  changes.  The  animal  body 
is  certainly  the  seat  of  greatly  varied  and  complex 
constructive  and  destructive  activities,  which  are  sus- 
tained by  the  matter  and  potential  energy  of  the  food. 
How  this  is  done  we  do  not  fully  understand,  but  we 
know  many  facts  which  are  of  great  scientific  and  prac- 
tical importance  and  which  the  feeder  must  consciously 
or  unconsciously  recognize  if  he  would  not  come  into 
conflict  with  immutable  laws. 


FUNCTIONS  OF   THE   MINERAL  COMPOUNDS   OF 
THE   FOOD 

We  have  learned  that  mineral  compounds  are  abun- 
dant in  the  animal  body.  The  tissues,  the  blood,  di- 
gestive fluids  and  especially  the  bony  framework  con- 
tain a  variety  of  these  bodies,  which  are  as  essential 
as  any  other  substances  to  the  building  and  mainte- 
nance of  the  animal  organism.  Bone  formation  with- 
out phosphoric  acid  and  lime  is  not  possible,  and  to 
deprive  the  digestive  juices  of  the  chlorine  and  soda 
which  they  contain  would  be  to  destroy  their  useful- 
ness. Young  animals  fail  to  develop  if  given  no 
mineral  food,  and  mature  animals  when  entirely  de- 
prived of  even  one  substance,  common  salt,  become 
weak,  inactive  and  finally  die.  Not  only  must  the 
growing  calf  have  the  ash  compounds  for  constructive 
purposes,  but  the   mature  ox  must   be   supplied   with 


Uses  of  Mineral  Compounds  —  Protein         153 

them  in  order  to  sustain  the  nutritive  functions.  It  is 
especiallj'  true  of  milch  cows,  which  store  combinations 
of  phosphoric  acid,  lime  and  potash  so  abundantly  in 
the  milk  that  they  must  have  an  adequate  supply  of 
these  substances.  Nothing  is  clearer  than  that  these 
materials  must  of  necessity  be  furnished  in  the  food. 
They  cannot  originate  in  the  animal,  neither  can  car- 
bon compounds  take  their  place. 

Nature  seems  to  have  made  generous  provision 
for  the  animals'  needs  along  this  line.  All  of  our 
home -raised  feeding  stuffs,  as  usuallj^  fed,  contain  in 
variety  and  quantity  all  that  is  needful  of  these  nu- 
trients except  for  poultry  perhaps.  Milk,  that  is  the 
exclusive  food  of  very  young  animals,  is  especially  cal- 
culated to  sustain  the  rapid  bone  formation  which  is 
taking  place.  It  is  only  when  feeding  is  one-sided,  as 
in  an  exclusive  corn  diet,  or  when  parts  of  a  grain  are 
removed,  that  we  need  fear  a  deficiency  of  the  neces- 
sary mineral  compounds. 

FUNCTIONS    OF    PROTEIN 

While  there  are  at  present  many  unsolved  problems 
relative  to  the  nutritive  offices  of  protein,  there  is  no 
reasonable  doubt  that  tlie  vegetable  proteids  are  the 
only  sources  of  similar  substances  in  the  animal  body. 
This  is  equivalent  to  a  statement  that  from  the  pro- 
teids are  formed  the  muscles,  the  connective  tissues, 
the  skin,  hair,  horn,  and  hoofs,  and  the  major  part  of 
the  tissues  of  the  secretive  and  excretive  organs;  in 
short,  that  they  are  the  source   of   a   large  proportion 


154  The  Feeding  of  Animals 

of  all  the  working  parts  of  the  animal's  body.  So 
far,  scientific  research  has  not  succeeded  in  demon- 
strating that  an  albuminoid  is  ever  synthesized  (built 
up  from  simple  compounds)  outside  of  the  plant.  It 
appears  that  bodies  of  this  class  must  come  to  animal 
life  fully  elaborated.  This  is  a  truth  of  great  sig- 
nificance even  in  its  relation  to  the  nutrition  of  farm 
animals.  The  nitrogenous  tissues  are  those  that  largely 
determine  the  vigor  and  quality  of  any  animal,  and  as 
these  are  formed  rapidly  in  the  early  stages  of  growth, 
a  normal  and  unrestricted  development  demands  an 
abundant  supply  of  proteid  food.  It  is  also  true  of 
mature  animals  that  sufficient  protein  is  not  only  nec- 
essary to  health  and  vigor,  but  it  is  essential  to  pro- 
duction that  is  satisfactory  in  quantity  and  quality. 

The  functions  of  protein  are  not  restricted,  how- 
ever, to  the  use  already  described.  According  to  ex- 
isting views,  it  is  utilized  in  more  ways  than  any 
other  class  of  nutrients.  It  was  held  at  one  time  by 
prominent  scientists  that  outside  the  vegetable  fats  it 
is  the  sole  source  of  animal  fats,  and  this  view  was, 
not  so  very  long  ago,  to  some  extent  accepted.  Indis- 
putable proof  to  the  contrary  is  now  in  our  possession, 
and  some  investigators  even  go  so  far  as  to  deny  the 
possibility  of  the  formation  of  fat  from  protein.  On 
this  point,  opinion  is  divided.  Certainly  we  must  be 
convinced  that  nitrogen  compounds  of  the  food  are, 
with  some  species,  not  the  most  important  source  of 
animal  fat,  for  various  investigators,  such  as  Lawes 
and  Gilbert,  Soxhlet,  and  others,  have  shown  upon  the 
basis   of    searching   experiments    that   sometimes   over 


I 


Cfses  of  Carhohydrates  155 

four -fifths  of  the  fat  stored  by  pigs  must  have  had 
its  origin  outside  the  food  protein  and  fat.  Besides 
all  this,  the  common  experience  of  feeders  that  foods 
highly  non- nitrogenous  are  often  the  most  efficient  for 
fattening  purposes  is  good  common -sense  evidence  that 
fat  formation  is  not  greatly  dependent  upon  the  pro- 
tein supply.  Nevertheless,  the  possibility  of  producing 
animal  fat  from  protein  is  not  disproved,  and  there  are 
several  considerations  which  make  it  seem  probable 
that  under  certain  conditions  this  does  occur. 

Protein  can  unquestionably  serve  as  fuel,  or,  in  other 
words,  as  a  source  of  energy.  The  amount  so  used 
depends  much  upon  the  animal  fed  and  the  character 
of  the  ration.  In  the  case  of  a  dog  eating  an  exclusive 
meat  diet  or  of  a  fattening  animal  which  receives  a 
ration  liberally  nitrogenous,  probably  the  greater  part 
of  the  protein  eaten  is  not  stored  but  is  used  as  fuel. 
With  milch  cows  or  young  animals  growing  vigor- 
ously, a  much  larger  proportion  escapes  oxidation. 
The  fuel  value  of  protein  will  be  discussed  later  under 
another  head. 

FUNCTIONS    OF    CARBOHYDRATES 

Carbohydrates  are  usually  characterized  as  the  fuel 
portion  of  the  food,  or  that  part  which  is  burned  to 
produce  the  various  forms  of  energy.  This  conception 
of  the  function  of  these  bodies  is  correct  in  the  sense 
that  in  the  case  of  ruminants  they  constitute  the 
larger  part  of  the  fuel,  although  not  the  whole  of  it. 
For  instance,  in  the  case  of  a  cow  eating  daily  sixteen 


156  The  Feeding  of  Animals 

pounds  of  digestible  organic  matter,  giving  thirty 
pounds  of  milk  containing  15  per  cent  of  solids, 
and  neither  gaining  nor  losing  flesh,  not  far  from 
five  pounds  of  this  organic  matter  would  be  found 
in  the  milk  and  urine,  leaving  about  eleven  pounds 
to  be  used  as  fuel,  about  a  pound  and  a  half  of 
which  might  be  derived  from  the  protein  and  fat, 
the  remainder,  or  9.5  pounds,  consisting  of  carbo- 
hydrates. If  a  fattening  steer  were  eating  the  same 
amount  of  the  same  kind  of  food  and  gaining  two 
pounds  of  live  weight  daily,  the  body  increase  and 
urine  would  contain  not  over  2.5  pounds  of  dry 
matter,  leaving  not  less  than  13.5  pounds  to  be  oxi- 
dized, of  which  twelve  pounds  might  consist  of  car- 
bohydrates and  fat,  mostly  the  former.  It  is  clear, 
then,  that  while  other  bodies  serve  as  fuel,  the  carbo- 
hydrates furnish  much  the  larger  part  of  that  which 
is  needed  for  this  use. 

Contrary  to  views  that  held  for  a  time,  it  is  now 
well  established  that  the  animal  fats  may  have  their 
source  in  the  carbohydrates ;  in  other  words,  starch 
and  sugar  and  related  bodies  may  serve  the  main 
purpose  in  feeding  animals  for  fattening.  In  many 
experiments,  notably  those  with  swine,  the  protein 
and  fat  of  the  food  have  fallen  far  short  of  ac- 
counting for  the  fat  in  the  body  increase,  some- 
times much  the  greater  part  of  the  latter  having 
no  possible  source  other  than  the  carbohydrates.  A 
practical  expression  of  this  general  conclusion  con- 
cerning the  fat -forming  function  of  carbohydrates  is 
seen    in  the  well -recognized  value  of  corn  meal  as    a 


Uses  of  the  Fats  —  Energy  157 

fattening  food,  a  feeding  stuff  nearly  seven -tenths  of 
which  consists  of  starch  and  its  allies.  Recent  experi- 
ments with  milch  cows  leave  scarcely  any  doubt  that 
milk  fat  may  also  be  derived  from  carbohydrates. 
These  more  recent  views  tend  to  magnify  the  impor- 
tance of  the  carbohydrates  as  nutrients. 

FUNCTIONS    OF   THE    FATS    AND    OILS 

So  far  as  is  at  present  known,  the  possible  uses  of 
the  food  fats  and  oils  and  of  the  carbohydrates  are  sim- 
ihir.  In  other  words,  both  may  serve  as  fuel  and  both 
may  be  a  source  of  animal  fat.  The  differences  are  that 
the  supply  of  carbohydrates  is  much  the  larger,  and 
the  fuel  value  of  a  unit  weight  of  fats  much  the  greater. 
Moreover,  it  seems  possible  for  a  vegetable  fat  to  be- 
come deposited  in  the  animal  without  essential  change, 
whereas  fat  formation  from  carbohydrates  involves 
complex  chemical  transformations. 

FOOD  AS  A  SOURCE  OF  ENERGY 

The  living  animal,  either  as  a  whole  or  in  some  of 
its  parts,  is  constantly  in  motion.  This  means  that 
the  animal  mechanism  is  ceaselessly  performing  work. 
Even  if  the  body  is  apparently  quiet,  the  heart  beats, 
pumping  blood  to  all  parts  of  the  body,  the  lungs  are 
expanded  and  contracted,  and  the  stomach  and  intes- 
tines keep  up  the  movements  which  are  essential  to 
digestion.  Besides,  a  living  body  is  the  seat  of  con- 
tinuous, invisible  and  complex  chemical  and  physical 
changes  that,  if  not  work  in  the  common  meaning  of 


158  The  Feeding  of  Animals 

the  term,  are  its  equivalent.  Walking,  trotting,  pull- 
ing, lifting,  pumping  blood,  breathing,  masticating, 
digesting  and  assimilating  food  represent,  then,  a  great 
variety  of  operations  of  those  living  machines  which  we 
have  named  horse,  ox,  cow  and  sheep. 

Now  work  requires  the  expenditure  of  energy.  The 
projection  of  a  rifle  ball  through  space  at  the  rate  of 
two  thousand  feet  per  second  is  work.  The  ball  does 
not  move  of  itself,  but  is  propelled  by  the  application 
of  the  energy  stored  in  a  powerful  explosive.  Back  of 
every  one  of  our  great  mechanical  operations,  such  as 
pumping,  grinding  and  moving  railroad  trains,  will 
always  be  found  some  sort  of  energy,  and  what  is  true 
of  machinery  made  of  wood  and  iron  is  equally  true  of 
that  made  of  bone  and  muscle.  The  fact  that  the 
mechanism  is  alive  does  not  abrogate  a  single  physical 
law,  so  that  the  fundamental  principles  of  energy  as 
applied  to  machines  are  as  fully  applicable  to  the  activ- 
ities of  animal  life. 

It  is  safe  to  go  farther,  and  say  that  the  animal 
organism  does  not  originate  energy.  Among  the  fun- 
damental conceptions  upon  which  all  our  knowledge 
of  chemical  and  physical  laws  rests  is  this,  that  energy 
and  matter  are  indestructible,  and,  moreover,  that  the 
sum  total  of  these  in  the  universe  is  unchangeable. 
If,  then,  the  horse  expends  the  muscular  energy  neces- 
sary to  draw  a  load  of  one  ton  over  ten  miles  of  road, 
the  equivalent  of  this  must  have  been  supplied  to  his 
body  from  some  outside  source.  He  could  not  create  it. 
We  know  that  this  is  so,  and  we  also  know  it  is  con- 
veyed to  the  animal  in  the  food. 


I 


Forms  of  Energy  159 

This  is  a  complex,  but  a  fascinating,  field  of  in- 
quiry; one  that  is  now  receiving  much  attention  in  our 
researches  after  a  more  intimate  understanding  of  the 
facts  and  principles  of  nutrition.  It  will  be  profitable, 
therefore,  for  us  to  gain  some  conception  of  the  knowl- 
edge of  this  kind,  which  so  far  seems  to  have  a  practical 
bearing  upon  our  subject. 

It  is  natural  to  first  ask,  What  is  energy?  This  is 
a  difficult  question  to  answer  in  a  popular  way,  and 
the  physicists'  definition  would  hardly  serve  our  pur- 
pose. All  we  can  do,  perhaps,  is  to  illustrate  it  by 
pointing  out  some  of  its  manifestations.  Let  us  re- 
sort to  an  old  illustration.  Every  farmer's  boy  has 
doubtless  seen  a  blacksmith  hammer  an  iron  rod  un- 
til it  was  red  hot.  The  motion  of  the  hammer-head 
descending  with  great  velocity  was  suddenly  arrested 
when  it  came  in  contact  with  the  rod.  This  descent 
of  the  hammer-head  illustrated  one  form  of  active 
energy;  viz.,  motion  of  a  mass  of  matter.  When 
the  hammer  met  the  iron  rod  on  the  anvil,  the 
mass  motion  ceased.  Was  the  energy  therefore  lost  ? 
Not  unless  our  fundamental  conception  is  wrong, 
and  we  find  that  in  this  case  it  is  not.  The  physicist 
teaches  us  that  the  motion  of  the  hammer-head,  a 
mass  of  matter,  was  communicated  to  the  smallest  par- 
ticles or  molecules  of  the  iron  rod,  and  as  the  vibra- 
tions of  the  molecule  increased  in  rapidity,  the  rod 
grew  hotter  and  hotter.  Here  we  have  another  illustra- 
tion of  energy;  viz.,  the  motion  of  the  molecule  or  heat. 

The  iron  rod  might  have  been  heated  in  another 
way, — by  plunging  it  into  burning  charcoal.  And  from 


160  The  Feeding  of  Animals 

whence  would  the  heat  energy  come  in  this  case  ? 
From  the  combustion  of  the  carbon.  Somehow,  when 
it  is  deposited  in  the  plant,  there  becomes  stored  in 
this  carbon,  in  a  way  about  which  we  can  only 
theorize,  what  perhaps  we  may  call  the  chemical  energy 
of  the  atom,  which,  when  combustion  occurs,  is  changed 
into  heat  or  molecule  motion.  From  these  phenomena 
we  learn  that  not  only  are  there  several  forms  of 
energy,  but  that  one  form  is  transferable  into  another. 
Perhaps  another  illustration  may  still  further  serve 
our  purpose.  A  small  dynamo  is  being  run  by  a  pair 
of  horses  working  in  a  tread  power  such  as  is  used 
for  threshing  grain.  The  horses  are  constantly  climb- 
ing up  a  moving  treadway  and  thereby  communicating 
motion  to  machinery.  This  motion  is,  by  the  dynamo, 
converted  into  electricity,  which,  by  passing  through 
the  carbon  film  of  an  incandescent  lamp  and  there 
meeting  resistance,  is  in  part,  at  least,  transformed  into 
heat.  We  have,  then,  in  a  chain,  muscular  effort, 
motion  of  the  mass  (pulleys,  wheels,  etc.),  electricity 
and  heat,  all  active  energy  and  all  transferable  the 
one  into  the  other.  This  is  a  fairly  good  picture  of 
what  goes  on  with  the  horse  himself,  externally  and 
internallj',  in  sustaining  life  and  performing  labor  for 
his  owner.  Back  of  it  all,  and  this  is  what  interests 
us,  is  the  animal's  food.  As  a  result  of  years  of 
patient  investigation,  it  has  become  known  that 
through  the  combustion  of  the  carbon  compounds  of 
vegetable  and  animal  origin,  which  serve  as  nutrients, 
chemical  energy  may  be  transformed  into  those  other 
forms  that  are  manifested   in  the  activities  of   living 


Measurement  of  Energy  161 

beings.  Wheu  we  ask  from  whence  comes  the  energy 
given  np  by  the  plant  compounds,  we  arrive  at  our 
hist  stage  of  inquiry.  Here  we  enter  the  domain  of 
phint  life,  and  it  is  a  notable  triumph  of  the  human 
intellect  that  we  are  able  to  declare  with  certainty  that 
the  ceaseless  and  multiple  activities  of  life  on  this 
planet  are  sustained  by  an  energy  which  comes  to  the 
plant  in  the  sun's  rays  through  almost  limitless  space. 
It  is  obvious  that  if  the  internal  and  external  work 
performed  by  the  animal  are  sustained,  by  the  food,  it 
is  desirable  to  measure  the  energy  available  in  differ- 
ent feeding  stuffs,  provided,  of  course,  that  they  differ 
in  this  respect,  as  we  know  they  do.  In  order  to 
measure  anything,  we  must  have  a  standard  or  unit  of 
measurement.  In  this  case  it  cannot  be  a  unit  of 
space  or  of  mass,  that  is,  we  cannot  declare  that  corn 
meal  contains  so  many  cubic  feet  or  pounds  of  avail- 
able energy.  Energy  has  neither  dimensions  nor  weight. 
If  we  measure  it  at  all,  it  must  be  by  units  of  tem- 
perature or  of  work  performed.  Units  of  this  kind 
are  applied  to  the  measurement  of  food  energ}-.  The 
one  most  commonly  in  use  is  the  Calorie,  this  being 
the  energy  which  in  terms  of  heat  is  sufficient  to  raise 
the  temperature  of  one  pound  of  water  4°  Fahren- 
heit. Expressed  in  terms  of  work,  the  Calori-e  is  very 
nearly  1.53  foot  tons,  or  in  other  words,  it  is  equiv- 
alent to  the  work  involved  in  lifting  one  ton  1.53 
feet.  Heat  units  are  expressed  in  both  the  ko'ge 
Calorie  and  the  small  calorie.  When  the  former  is  in- 
dicated, the  word  begins  with  a  capital  letter.  The 
Calorie  represents  1,000  calories. 


162  The  Feeding  of  AnimaJs 


^ 


The  total  euergy  or  heat  units  developed  in  the 
combustion  of  feeding  stuffs  is  determined  in  an  ap- 
paratus called  a  calorimeter.  The  latest  form  of  this 
device  is  one  in  which  the  ground  hay  is  burned  under 
pressure  in  the  presence  of  pure  oxygen,  and  the  heat 
evolved  is  all  used  in  warming  a  known  weight  of 
water.  Data  are  thus  obtained  from  which  it  is  possi- 
ble to  calculate  the  Calories  in  the  particular  material 
burned.  The  energy  value  of  single  compounds,  such 
as  albumin,  starch  and  sugar,  may  also  be  found  in 
the  same  way,  as  has  been  done  in  a  large  number  of 
instances.  These  data  show  that  the  heat  resulting  from 
the  combustion  of  the  compounds  of  the  same  class  is 
not  the  same  in  all  cases.  The  value  in  large  Calories 
of  one  gram  (about  one -twenty -eighth  of  an  ounce) 
of  the  several  nutrients  is  shown  in  the  following  table: 

Albuminoids,  etc. 

Cal.  Cal. 

Wheat  gluten 5.99  Egg  albumin 5.73 

Gliadin 5.92  Muscle  (pure) 5.72 

Glutenin 5.88  Blood  fibrin 5.64 

Plant  fibrin 5.94  Peptone 5.30 

Serum  albumin 5.92  Wool 5.51 

Milk  casein 5.86  Gelatin 5.27 

Yolk  of  egg 5.84  Asparagin  (amide) 3.45 

Carhohydrates  ^^.^j  Fats                 ^^^ 

Starch 4.18      Of  swine 9.38 

Cellulose 4.18      Of  oxen 9.38 

Glucose   3.74      Of  sheep 9.41 

Cane  sugar 3.95       Maize  oil 9.28 

Milk  sugar 3.95      Olive  oil 9.47 

Maltose 3.95  Ether  extract  of  oats. . .  8.93 

Zylose 3.74  Ether  extract  of  barley  •   9.07 


Availahle    Energy  163 

The  heat  vahies  of  a  gram  of  the  dry  substance 
of  various  cattle  foods,  which  is  a  mixture  of  the 
several  nutrients,  was  found  by  recent  determinations 
to  be  the  following,  expressed  in  small  calories: 

cal.  cal. 

Mixed  hay 4494  Corn  meal 4471 

Alfalfa  hay 4478  Linseed  meal   5040 

Oat  straw 4480  Flaxseed  meal 6935 

Sugar  beets 3931  Kice  meal 4400 

These  figures  mean  that  when  a  gram  of  each  of 
these  materials  is  wholly  burned  the  heat  produced  is 
as  stated. 

Availahle  energy. —  We  must  distinguish,  however, 
between  the  heat  produced  when  any  food  substance  is 
wholly  oxidized  in  a  calorimeter  and  the  heat  or  energy 
which  is  available  when  the  same  material  is  applied  to 
physiological  uses.  It  never  happens  that  the  combus- 
tible portion  of  a  ration  is  entirely  burned  in  the  animal. 

In  the  first  place,  the  food  of  domestic  animals  is 
practically  never  all  digested  and,  as  only  the  digested 
portion  furnishes  energy,  the  available  fuel  value  of  a 
ration  must  be  based  primarily,  not  upon  the  total 
quantity  of  dry  matter  it  represents,  but  upon  the 
amount  which  is  dissolved  and  passes  into  the  blood. 
If  all  feeding  stuffs  or  rations  were  digested  in  the 
same  proportion  and  with  the  same  ease,  their  total 
fuel  values  might  show  their  relative  energy  worth,  but 
as  digestion  coefficients  for  dry  matter  vary  from  less 
than  50  per  cent  with  the  straws  to  nearly  90  per  cent 
with  some  of  the  cereal  products,  it  is  evident  that  the 
fuel  waste  in  the  feces  is  not  uniform. 


164  The  Feeding  of  Animals 

III  the  second  place,  the  digested  proteids  are  never 
fully  burned.  A  portion  of  these  compounds  always 
passes  off  in  the  urine  unoxidized,  the  fuel  value  of 
which  is  lost  to  the  animal.  For  this  reason  the  avail- 
able energy  of  the  proteids  is  about  one -fourth  less 
than  the  total. 

In  the  third  place,  there  is,  with  ruminants  and 
horses  at  least,  an  escape  from  the  alimentary  canal 
of  unconsumed  gases,  due  to  the  fermentations  which 
take  place  during  digestion.  These  gases,  mostly 
methane  (marsh  gas),  have  their  source  in  the  carbo- 
hydrates, and  Kellner  found  them  to  represent  from 
10  to  20  per  cent  of  the  total  energy  value  of  the 
dry  substance  digested  from  various  materials.  From 
twenty  experiments,  upon  five  different  animals,  Kiihn 
found  the  loss  in  methane  to  be  over  one -seventh  the 
energy  of  the  digested  crude  fiber  and  nitrogen -free 
extract. 

We  are  to  understand,  then,  that  the  availahle 
energy  of  a  ration  is  represented  by  the  fuel  value  of 
the  dry  matter  which  is  digested  from  it,  minus  the 
dry  matter  of  the  urine  and  that  lost  in  gases. 

If,  however,  we  wish  to  know  the  actual  energy 
gain  to  the  animal  from  a  particular  ration,  we  must 
go  farther  than  a  determination  of  its  available  energy. 

Net  energy. — Within  a  comparatively  short  time  we 
have  begun  to  speak  of  the  net  energy  of  foods,  and  as' 
this  is  a  practical  consideration  which  is  likely  to  be 
the  subject  of  much  future  discussion,  it  is  well  to  no- 
tice it  in  an  explanatory  way.  As  we  have  learned, 
food   is  not  applied  to  use  until  it  reaches  the  blood. 


Energtj  Loss  in    VTorl:  of  Bigestion  165 

Between  the  time  when  it  is  taken  into  the  month  and 
when  it  passes  into  the  circulation,  it  must  have  work 
expended  on  it  in  the  way  of  mastication,  solution  and 
moving  it  along  the  digestive  tract,  and  it  appears 
highly  probable  that  the  amount  of  this  work  per 
pound  of  food  must  vary  greatly  in  different  cases. 
In  fact,  we  know  this  is  so  from  the  result  of  some 
masterly  investigations  conducted  by  Zuntz  in  Ger- 
many. By  means  of  various  devices  and  methods,  a 
description  of  which  would  be  out  of  place  here,  he 
measured  the  oxygen  consumption  necessary  to  sustain 
the  mechanical  energy  of  mastication  and  digestion, 
and  he  calculates  from  his  determinations  that  the  fol- 
lowing heat  units  represented  the  energy  used  in 
cheAving   certain  feeding  stuffs: 

cal.  cal. 

1  pound  hay 76       1  pound  com 6  % 

1  pound  oats 21       Green  fodder  equal   to   1 

pound  of  hay 47 

The  differences  revealed  by  these  figures  are  inter- 
esting and  important.  Chewing  green  food  cost  in 
labor  only  about  62  per  cent  of  the  effort  required  to 
masticate  its  equivalent  of  dry  haj^  the  proportions  of 
labor  for  hay,  oats  and  corn  being  in  the  ratio  of 
100,  27  and  8%. 

This  author  goes  further  and  calculates  that  the 
work  of  mastication  and  digestion  combined  is  48 
per  cent  of  the  energy  value  of  the  digested  mate- 
rial from  hay  and  19.7  per  cent  of  that  from  oats. 
He  also  makes  the  statement  that  in  general  the  coarse 
foods  have  20  per  cent  less  net  energy  value  than  the 


166  The  Feeding  of  Anwtals 

grains.  All  these  deductions  are  based  upon  the  excess 
of  oxygen  used  by  the  animal  when  engaged  in  the  work 
of  chewing  and  digestion,  over  that  used  when  at  rest. 
It  follows  from  these  results  that  anything  in  the  way  of 
growth  or  treatment  of  a  fodder  which  tends  to  toughen 
or  harden  the  tissue  reduces  the  net  energy  value.  It 
has  long  been  believed,  though  perhaps  not  proved,  that 
grain  foods  are  superior  to  coarse  foods  to  an  extent  not 
accounted  for  by  the  differences  in  digestibility,  and  if 
this  is  a  fact,  it  is  explained  in  part  by  the  unlike  com- 
position but  is  to  some  extent  undoubtedly  due  to  the 
greater  effort  of  chewing  and  digesting  the  fodders. 

If  we  wish  to  ascertain  the  comparative  energy  worth 
of  two  unlike  rations,  it  would  obviously  be  incorrect  to 
multiply  the  total  quantities  of  protein,  carbohj^lrates 
and  fats  in  each  by  the  unit  heat  values  in  order  to 
ascertain  the  relative  energy  gain  to  the  animal  body. 

To  recapitulate,  we  may  define  avaUcible  energy  as 
total  energy  minus  that  which  is  lost  in  the  excreta  and 
in  gases  which  escape,  and  net  energy  as  available  energy 
minus  the  cost  of  digestion  and  of  preparing  the  food  for 
use.    Net  energy  is  the  balance  of  profit  to  the  animal. 

ENERGY   RELATIONS    OF   THE    SEVERAL   NUTRIENTS 

As  has  been  pointed  out,  the  animal  body  is  the  field 
of  numerous  mechanical  a(;tivities.  What  is  the  rela- 
tion of  the  several  nutrients  to  these  manifestations  of 
vital  energy  is  an  interesting  and  in  some  ways  an 
intensely  practical  matter.  For  instance,  has  protein 
a  peculiar   function    in    the    maintenance    of   muscular 


Maintenance  of  Muscular  Effort  167 

activity  whieh  no  other  nutrients  have  ?  The  belief 
prevailed  at  one  time  that  muscular  contraction  caused 
a  wasting  of  the  muscle  substance  which  must  be  re- 
placed by  the  proteid  compounds  of  the  food;  in  other 
words,  protein  alone  was  believed  to  sustain  the  work  of 
the  animal  body,  both  internal  and  external.  It  would 
follow  from  this  that  the  more  work  is  done  the  more 
protein  is  needed.  This  view  is  no  longer  held.  The 
more  exact  methods  of  modern  research  have  revealed 
the  fact  that  an  increase  of  muscular  effort,  even  up  to  a 
severe  point,  increases  but  little,  if  any,  the  nitrogen 
compounds  of  the  urine,  these  being  the  measure  of  the 
protein  that  is  destroyed.  There  has  come  to  light  a 
corresponding  fact  that  the  consumption  of  fuel  in  the 
body  other  than  proteids  increases  proportionately  with 
the  increase  of  work.  This  means  that  as  animals  are 
ordinarily  fed  mechanical  work  is  largely  sustained 
through  the  combustion  of  carbohydrates  and  fats,  and 
that  while  for  reasons  we  do  not  yet  wholly  understand 
a  fairly  generous  amount  of  protein  seems  to  promote 
the  well-being  of  a  draft  animal,  the  non -nitrogenous 
nutrients  mostly  supply  the  extra  energy  demanded  for 
the  labor. 

Heat  relations.  —  The  question  is  very  naturally 
asked,  As  no  energy  is  lost,  into  what  is  the  energy  of 
muscular  contraction  converted,  as,  for  instance,  that 
required  for  walking,  the  beating  of  the  heart  and  the 
work  of  the  intestines  ?  It  is  concluded  bj'  physiologists 
that  muscular  energy  used  by  the  animal  is  partly  trans- 
formed into  external  motion  and  partly  into  heat,  and 
this  certainly  is  consistent  with  facts  as  observed.     Vio- 


168  The  Feeding  of  Animals 

lent  exercise  by  the  animal  greatly  increases  the  produc- 
tion of  heat.  We  know  this  is  so  because  under  these 
conditions  an  increased  amount  of  blood  is  thrown  to 
the  surface  of  the  body,  thereby  greatly  increasing  the 
loss  of  heat  by  radiation;  perspiration  sets  in  and  with 
it  the  consequent  evaporation  of  much  more  moisture, 
thus  disposing  of  much  heat.  The  dog,  and  sometimes 
other  animals,  pants  and  thereby  causes  a  large  loss  of 
heat  from  the  expanded  surface  of  the  moist  tongue. 
All  this  occurs  without  reducing  the  body  temperature 
below  the  normal.  In  fact,  nature  adopts  these  various 
devices,  such  as  increased  circulation  of  the  blood  and 
perspiration,  in  order  to  regulate  the  body  temperature 
and  prevent  its  rising  above  the  proper  point.  The 
explanation  of  this  greater  heat  during  labor  is  that  the 
mechanical  energy  manifested  by  the  muscles  is  con- 
verted to  heat,  which  under  circumstances  of  severe 
exercise  is  more  than  enough  to  keep  the  body  at  its 
usual  temperature  and  maintain  the  usual  radiation. 
When  it  is  severely'  cold,  on  the  other  hand,  vigorous 
exercise  is  sometimes  necessary  in  order  to  keep  suffi- 
ciently warm. 

The  view  is  held  by  some  that  all  body  heat  is  a 
secondary  product,  that  combustion  first  supports  mus- 
cular activity  which  (changes  to  heat,  in  fact,  that  no 
food  is  burned  primarily  to  keep  the  animal  warm. 
Convincing  proof  of  this  position  is  still  lacking,  how- 
ever. There  appears  to  be  no  good  reason  why  we 
should  deny  the  possibility  of  combustion  of  food  for 
the  specific  purpose  of  warming  the  body.  Certainly 
an  Arctic  climate  causes  a  consumption  of  food  which 


Heat    Regulation  169 

ill  kind  and  quantity  would  be  impracticable  in  the 
tropics,  and  this  too,  even  if  there  is  no  apparent  in- 
crease of  internal  or  external  work.  This  would  seem 
to  indicate  the  direct  oxidation  of  food  for  heating 
purposes.  In  any  case,  animal  heat  is  sustained  either 
directly  or  indirectly  by  the  burning  of  the  nutrients. 


CHAPTER   XII 

PHYSIOLOGICAL   VALUES   OF   THE  NUTRIENTS 

The  preceding  discussion  of  the  physiological  uses 
of  the  various  nutrients  has  dealt  largely  with  them 
as  classes.  The  special  functions  and  relative  values 
of  individual  compounds  within  the  same  class  or  of 
the  different  classes  have  not  been  considered.  We 
know,  for  instance,  that  the  albuminoids  are  in  a 
general  way  flesh -formers,  or  fat -formers,  or  heat- 
formers,  but  we  desire  still  further  information  as  to 
the  relative  efficiency  of  the  individual  albuminoids  for 
any  specific  purp()Se.  Are  some  albuminoids  more  use- 
ful than  others  in  aiding  milk  secretion  ?  Similar 
knowledge  concerning  the  non-nitrogenous  nutrients  is 
important.  How  valuable  physiologically  is  cellulose 
as  compared  with  starch  ? 

Again  we  are  convinced  that  both  the  carbohy- 
drates and  the  vegetable  fats  may  be  sources  of  animal 
fats,  but  we  are  bound  to  inquire  what  is  the  relative 
importance  of  these  groups  of  compounds  as  fat- 
formers  in  the  animal  body. 

It  is  easy  to  understand  that  knowledge  of  this 
kind  would  be  valuable.  We  are  coming  to  know  a 
great  deal  about  the  composition  of  the  various  cattle 
foods,  and  if  we  could  ascertain   the  exact  physiologi- 

(170) 


Relative  Energij  and   Production    Values  171 

cal  uses  and  relative  values  of  even  the  most  promi- 
nent individual  compounds,  we  would  be  able  to  make 
somewhat  definite  comparisons  of  the  different  feeding 
stuffs.  It  must  be  confessed  that  information  of  this 
specific  kind  is  not  as  complete  as  one  could  wish. 
Its  acquirement  is  very  difficult  and  its  present  status 
is  in  some  particulars  unsatisfactory.  Investigations 
so  far  conducted  are  not  only  insufficient  to  final  con- 
clusions, but  researches  by  different  observers  have  re- 
sulted in  a  conflict  of  opinion  in  some  cases. 

RELATIVE  ENERGY  AND  PRODUCTION  VALUES  OF  THE 
NUTRIENTS  SINGLY  AND  AS  CLASSES 

It  is  satisfactorily  established,  as  we  have  seen, 
that  protein,  carbohydrates  and  fats  have  certain  func- 
tions in  common,  that  is,  that  all  three  classes  are 
utilized  as  fuel,  and  that  both  carbohydrates  and  fats, 
and  perhaps  protein,  may  be  a  source  of  body  fat. 
The  question  naturally  arises.  What  is  the  relative 
value  of  these  unlike  nutrients  as  a  source  of  energy 
and  as  fat-formers?  Moreover,  as  each  class  is  made 
up  of  a  variety  of  substances,  unlike  in  physical  and 
chemical  characteristics,  can  we  consider  the  individual 
compounds  within  the  same  class  as  nutritively  equal  ? 

Relative  energy  values.— As  a  source  of  energy,  the 
carbohydrates  and  their  allies  are  properly  regarded  as 
of  first .  importance  because  of  their  large  relative  use 
as  a  fuel  supply.  These  bodies,  so  far  as  they  are 
digestible,  have  been  considered  in  formulating  rations 
as    of    practically  equal  value.     It  is  well  known  that 


172  The  Feeding  of  Animals 

this  is  a  doubtful  assumption.  The  nitrogen-free  ex- 
tract digested  from  the  fodders  is  much  more  largely 
derived  from  crude  fiber  and  the  gums  than  that  di- 
gested from  the  grains,  starch  being  predominant  in 
the  latter,  and  we  are  not  justified  in  concluding, 
except  from  reliable  evidence,  that  the  materials  from 
the  two  sources  are  similar  and  equivalent  as  nutrients; 
in  fact,  some  investigators  believe  the  reverse  to  be 
true. 

If  we  accept  the  heat  of  combustion  of  the  carbo- 
hydrates and  similar  substances  when  burned  in  a  cal- 
orimeter as  the  measure  of  their  energy  value,  we  have 
definite  figures.  The  heats  of  combustion  of  the  com- 
pounds found  in  the  nitrogen-free  extract  have  been 
found  to  vary  from  3.7  to  4.2  Calories  per  gram. 
This  indicates  no  great  difference  in  value  for  the 
production  of  heat  energy.  We  are  not  sure,  how- 
ever, that  what  is  true  of  simple,  rapid  combustion  is 
true  of  physiological  use.  Certain  related  facts  must 
be  considered.  Because  of  Tappeiner's  conclusion  that 
the  fermentations  to  which  cellulose  is  subject,  break 
it  up  mostly  into  gases  and  organic  acids  which  he 
regarded  as  largely  not  useful  to  the  animal,  the  view 
has  more  or  less  prevailed  that  digested  crude  fiber  is 
greatly  inferior  to  starch  as  a  nutrient.  More  recent 
investigations  throw  doubt  upon  the  correctness  of 
this  view,  and  the  trend  of  opinion  now  seems  to  be 
towards  regarding  cellulose  as  taking  practically  the 
same  place  in  nutrition,  apart  from  ease  of  digestion, 
that  starch  does.  It  appears  that  the  fermentations 
in  the  digestive  tract  of  starch,  sugar  and  other  carbo- 


Value   of  the  Nutrients  173 

hydrates  also  give  rise  to  gases  which  pass  off  nncon- 
sumecl,  though  perhaps  not  to  the  same  extent  as  is 
the  case  with  crude  fiber,  and  several  observers  de- 
clare that  digested  crude  fiber  is  no  less  nutritively 
efficient  in  a  maintenance  ration  than  the  more  soluble 
compounds  of  the  nitrogen -free  extract. 

The  question  has  been  raised  as  to  whether  the 
gums  (pentosans)  which  exist  so  abundantly  in  many 
coarse  foods  and  in  some  grain  products,  like  wheat 
bran,  are  not  inferior  to  the  other  more  soluble  carbo- 
hydrates. It  has  been  observed  that  the  sugars  which 
result  from  the  action  of  ferments  on  these  bodies 
have,  in  some  instances,  not  been  oxidized,  but  have 
passed  off  in  the  urine  as  such.  It  appears  doubtful 
whether  under  normal  and  usual  conditions  this  occurs 
to  any  extent.  The  gums  are  constantly  present  in  all 
rations  for  farm  animals,  and  we  have  no  reason  for 
believing  that  the  pentose  (gum)  sugars  are  constant 
ingredients  of  their  urine. 

The  comparative  physiological  values  of  individual 
albuminoids  and  fats  we  do  not  know  very  much  about, 
other  than  what  we  may  judge  from  the  determinations 
of  heats  of  combustion.  In  experimental  work  single 
compounds  have  been  but  little  studied.  The  conclu- 
sions reached  have  usually  been  based  upon  the  results 
of  feeding  mixtures  of  individual  albuminoids  and  fats 
as  they  ordinarily  exist  in  plants. 

Determinations  of  the  heats  of  combustion  of  single 
and  mixed  albuminoids  and  fats  from  various  sources 
show  a  variation  of  from  5.6  to  6  Cal.  per  gram  for 
the  former  and  from  9.2  to  9.6  Cal.  for  the  latter.    The 


174  The  Feeding  of  Animals 

variation  for  the  same  class  is  seen  not  to  be  large,  but 
whether  the  animal  derives  energy  in  similar  propor- 
tions must  be  decided  by  experimental  evidence. 

In  recent  j^ears  much  attention  has  been  given  ex- 
perimentally to  the  physiological  values  of  the  nutrients. 
Among  the  most  painstaking  and  extensive  investiga- 
tions of  this  sort  are  those  conducted  at  Mockern  by 
Kellner  and  his  associates.  This  work  includes  forty- 
four  metabolism  experiments,  each  of  fourteen  days' 
duration,  and  one  hundred  and  eighty -four  respiration 
experiments,  each  of  twenty-four  hours'  duration.  In 
order  to  secure  the  desired  data,  there  was  added  to  a 
basal  ration  gluten,  oil,  potato  starch,  extracted  straw 
(mostly  cellulose  freed  from  incrusting  and  accom- 
panying compounds),  meadow  hay,  oat  straw,  and  well- 
ripened  wheat  straw.  From  the  results  obtained, 
through  exact  measurements  of  the  ingested  food,  the 
excreta  and  the  products  of  respiration, — thus  making 
it  possible  to  determine  the  relation  of  each  substance  to 
the  maintenance  of  the  animal  and  to  the  storage  of 
flesh  and  fat, — Kellner  worked  out  both  the  energy  and 
the  production  values  of  the  experimental  materials. 
While  the  figures  given  should  not  be  regarded  as 
final,  they  have  behind  them  so  much  careful  and  severe 
investigation  that  they  must  be  accepted  as  having 
great  weight.  They  at  least  correctly  record  what 
happened  with  particular  animals. 

In  presenting  these  results  a  distinction  is  made 
between  available  energj^  value  and  production  or  net 
value.  It  is  the  former  which  interests  us  at  this  point, 
and  it  is  this  which  is  shown  in  the  following  figures: 


Available   Eufrgy    in    Typical   Nutrients         175 

Total  heat  value  Per  cent  of  Available  heat  Comparative 

of  1  gram  of  loss  in  urine  value  for  1  gram  available  heat 

digested  and  gases-  digested  value  when 

organic  matter  methane  organic  matter  starch  is  100 

cal.  Per  cent  cal. 

Starch 4183  10.lt  3760  100 

Extracted  straw..  4247  14. t  3651  97 

Molasses 4075  10  4  3645  97 

Meadow  hay 4480  18.7  3640  97 

Oat  straw 4513  16.9  3747  100 

Wheat  straw 4470  25.6  3327  88 

Gluten 6148  19.3tt  4958  132 

Peanut  oil 8821  8821  235 

tLoss  wholly  from  methane.  ttLoss  wholly  in  urine. 

The  available  energy  is  seen  in  the  total  energy  of 
the  digested  organic  matter  less  that  which  is  lost  in 
the  urine  and  from  fermentations  which  produce  the 
gas -methane. 

These  figures  show  the  energy  or  heat  furnished  to 
the  animal  by  the  different  materials  after  deducting 
losses.  They  also  represent  the  heat  production  when 
the  substances  were  fed  in  a  maintenance  ration, 
and  as  Rubner  has  demonstrated  that  the  heat  lost 
from  the  animal  that  is  eating  just  a  maintenance 
ration  is  a  measure  of  the  animal's  use  of  food, 
these  values  show  what  the  different  substances  were 
w^orth  for  maintenance  purposes.  It  appears  that 
in  these  investigations  the  sugars  of  molasses,  ex- 
tracted cellulose  and  the  material  digested  from  the 
coarse  foods  containg  much  cellulose  and  gums  sup- 
plied practically  the  same  available  energy  to  the 
animal  that  starch  did,  wheat  straw  excepted. 

Relative  production  values  of  the  different  nutrients. 
—  If  we  calculate  the  fat -forming  value  of  protein  and 


176  Tlie  Feeding  of  Animals 

starch  on  a  purely  theoretical  basis  as  Hemieberg  did 
some  years  ago,  it  would  appear  that  100  parts  of  body 
fat  can  be  obtained  from  194  parts  of  albuminoids  or 
244  parts  of  starch.  The  fat  factor  of  albuminoids 
would  be  therefore  51.4%  and  of  starch  41%.  The 
equivalence  of  food  fat  in  terms  of  body  fat  has  never 
been  expressed  on  such  a  basis,  though  it  is  customary 
to  assume  that  the  fat  of  the  food  may  cause  the  pro- 
duction of  an  equal  quantity  of  body  fat  or  milk  fat, 
an  assumption  which  has  no  foundation  whatever. 

These  theoretical  figures  are  an  attempt  to  show 
Avhat  protein  and  starch  may  do  when  actually  used 
for  storage  purposes.  They  cannot  be  accepted  as 
meaning  much  in  indicating  how  the  food  is  really 
used  in  practice.  It  is  probable  that  the  excess  of 
food  over  and  above  maintenance  is  never  all  used 
for  production  according  to  the  theoretical  possibilities 
based  upon  chemical  rearrangements  of  compounds. 
Certainly  the  production  from  a  given  quantity  of 
food  varies  greatly  under  unlike  conditions.  It  can 
scarcely  be  doubted  that  the  proportion  of  the  avail- 
able nutrients  which  are  consumed,  that  is,  burned  as 
fuel,  increases  as  the  ration  increases  above  what  is 
needed  for  maintenance,  and  inversely  the  proportion 
of  the  nutrients  stored  in  the  body  as  flesh  and 
fat  is  less  the  greater  is  the  quantity  fed  in  excess 
of  the  demands  for  maintenance.  A  large  excess  over 
maintenance  is  relatively  less  efficient  than  a  small 
one.  There  comes  a  point  where  additional  food  pro- 
duces no  additional  gain,  but  only  additional  consump- 
tion.    The  age  of  the  growing  animal  and  the  condition 


Productive    Value    of   Typical   Nutrients         111 

of  a  fattening  animal  also  modify  the  efficiency  of  the 
food  for  production  purposes,  as  does  the  period  of  lac- 
tation with  a  cow.  With  all  these  variations  we  have 
no  averages  which  express  with  any  definiteness  the 
relative  practical  production  value  of  the  different  nu- 
trients. Nevertheless  this  question  has  been  the  sub- 
ject of  severe  and  extended  investigation,  and  some  of 
the  results  have  given  valuable  information. 

Henneberg  and  Pfeiffer  estimate  that  in  experiments 
with  sheep  the  protein  in  excess  of  maintenance  caused 
the  production  of  from  30.7  to  41.1  parts  of  fat  for 
each  100  parts  of  protein.  It  is  not  shown  that  the 
fat  came  directly  from  the  protein  or  from  the  carbo- 
hydrates which  the  excess  of  protein  replaced  in  other 
uses.  Experiments  by  Kiihn  are  made  the  basis  of 
the  conclusion  that  1  pound  of  starch  supported  the 
storage  of  .2  pounds  of  fat. 

The  most  reliable  and  extensive  data  as  to  pro- 
ductive values  are  those  already  referred  to  as  having 
been  reached  by  Kellner  and  others  at  Mockern.  They 
are  summarized  in  the  following  table: 

Heat  Mjiinteii-  Percentage  Productive   Compara- 

valiie  auce  value  Mainten-  value  tive 

gram  graui  ance  value  gram        productive 

organic  organic  applied  to  organic  value, 

matter  matter  production      matter  starch  100 

cal.  cal.  Per  cent  cal. 

Starch 4183  3760  58.9  2215  100 

Extracted  straw...   4247  3651  63.1  2304  104 

Molasses 4075  3645  63.6  2310  104 

Meadow  hay 4480  3640  41.5  1512  68 

Oat  straw 4513  3747  37.6  1409  64 

Wheat  straw 4470  3327  17.8  592  27 

Gluten 6148  4958  45.2  2241  101 

Peanut  oil 8821  8821  56.3  4966  224 

L 


178  The  Feeding  of  Animals 

The  productive  value  is  stated  in  terms  of  the 
available  energy  less  (1)  the  energy  devoted  to  the 
work  of  chewing  and  digestion,  and  (2)  that  which  is 
appropriated  to  the  molecular  rearrangement  of  the  di- 
gested compounds  which  are  transferred  to  the  body 
substance. 

These  being  the  factors  which  diminish  productive 
value,  it  is  easy  to  understand  how  the  usefulness  of  a 
nutrient  is  somewhat  determined  by  its  source.  When 
it  is  contained  in  a  coarse  fodder  like  straw  where  the 
work  of  chewing  and  digestion  is  large  and  where, 
because  of  its  physical  condition,  the  fodder  is  slowly 
acted  upon  by  the  digestive  fluids  and  is  thus  subject 
for  a  long  time  to  the  action  of  micro-organisms,  the 
nutrient  is  less  valuable  than  when  supplied  to  the  ani- 
mal in  grain  where  the  work  of  mastication,  digestion 
and  solution  is  a  minimum.  Starch,  extracted  straw 
and  molasses,  requiring  no  energy  for  mastication  and 
but  little  for  solution,  supply  digested  material  which 
Kellner  found  to  be  four  times  as  valuable  for  pro- 
duction as  that  coming  from  ripe  wheat  straw. 

The  foregoing  figures  do  not  tell  us  how  much  a 
steer  would  gain  daily  when  fed  upon  a  certain  quantity 
of  these  nutrients,  but  they  do  indicate  in  a  general 
way  what  is  the  relative  efficiency  of  the  nutrients 
when  derived  from  given  sources.  They  give  us  a 
scientific  explanation  of  the  fact  that  coarse  foods  are 
not  adapted  to  rapid  production. 

Relative  imjyortance  of  the  protein  compounds.  — 
Much  prominence  has  been  given  to  the  fact  that 
protein  includes  several  groups  of  nitrogen  compounds 


Differences   in  Protein   Compounds  179 

quite  unlike  in  character.  We  know  also  that  these 
groups  exist  in  cattle  foods  in  unlike  proportions. 
For  example,  a  much  larger  part  of  the  protein  of 
roots  consists  of  amides  than  is  the  case  with  the 
grains,  the  protein  of  the  latter  being  correspondingly 
richer  in  albuminoids.  If,  therefore,  albuminoids  and 
amides  differ  in  function  or  value,  we  have  established 
one  point  of  unlikeness  between  cornmeal  and  turnips. 
The  testimony  so  far  obtained  is  quite  consistent  in 
one  direction,  and  indicates  that  the  flesh -forming 
function  is  confined  to  the  true  albuminoids.  This 
means  that  gelatin,  amides  (asparagin,  etc.),  extrac- 
tives (creatin,  etc.),  cannot  supply  real  muscle-build- 
ing material.  These  non-proteids  have  nutritive  value, 
however.  Experiments  with  gelatin  and  asparagin 
have  led  to  the  conclusion  that  their  presence  in  the 
ration  so  protects  the  albuminoids  from  consumption 
that  the  latter  may  have  their  maximum  use  as  flesh- 
and  milk-formei's.  The  extractives  seem  to  have  a 
peculiar  place  among  the  nutrients.  They  are  not 
regarded  as  flesh -formers,  or  as  fuel,  but  so  far  as 
is  known  they  act  merely  as  stimulants  of  the  nervous 
system. 

The  albuminoids  are  the  only  flesh -formers.  There 
are,  however,  many  albuminoids,  and  they  differ  among 
themselves  as  raw  material  out  of  which  to  construct 
the  primary  tissues  of  the  animal  body.  Can  albu- 
mins do  what  globulins  cannot  ?  Are  nucleins  su- 
perior to  albumins  for  special  purposes  f  Not  much 
that  is  definite  can  be  said  on  this  point.  Because 
the  various  nitrogenous  feeding  stuffs  are  so  generally 


180  The  Feeding  of  AnimoJs 

interchangeable  in  the  ration,  without  marked  effect 
upon  its  efficiency  when  the  protein  supply  is  not 
diminished,  it  seems  probable  that  the  albuminoids  are 
largely  interchangeable  in  use.  On  the  other  hand, 
certain  observed  facts  throw  doubt  on  this  view.  For 
example,  w^ell- conducted  experiments  show  that  animal 
protein  is  superior  to  vegetable  protein  as  food  for 
ducks,  when  the  two  kinds  are  supplied  in  equally 
digestible  quantities.  It  is  possible  that  there  are 
other  differences  in  the  effect  of  the  protein  from  un- 
like sources  which  the  ordinary  methods  of  observation 
have  not  been  competent  to  detect. 

One  interesting  question  which  has  been  consid- 
ered, is  whether  the  special  nuclein  bodies  (albu- 
minoids containing  phosphorus)  w^hich  are  found  so 
abundantly  in  eggs  and  in  milk  must  be  supplied  as 
such  in  the  food,  or  whether  they  may  be  built  up  in 
the  animal  from  other  albuminoids  and  phosphates.  If 
we  could  learn  that  the  food  must  contain  these  pe- 
culiar albuminoids  all  ready  for  use,  then  we  would  have 
a  valuable  suggestion  for  feeding  cows  and  poultry. 
It  now  seems  improbable  that  this  is  the  case.  The 
sea  salmon,  which,  during  its  stay  up  the  river,  is 
believed  to  take  no  food,  undoubtedly  produces  large 
masses  of  eggs  from  the  body  substance,  and  it  seems 
unlikely  that  so  much  nuclein  as  is  needed  exists  in 
the  flesh.  If  a  cow  gives  thirty  pounds  of  milk  daily, 
nearly  or  quite  a  pound  of  casein  must  come  from 
somewhere,  and  there  is  no  evidence  that  any  ordinary 
ration  would  contain  so  large  a  quantity  of  phosphorized 
albuminoids.     Hens'  eggs  are  rich  in  nuclein,  beyond 


Differences  in   Protein    Compounds  181 

anj'  amount  which  the  food  seems  likely  to  supply. 
Notwithstaudinof  this  indirect  evidence,  it  cannot  be 
safely  affirmed  that  one  albuminoid  does  not  pos- 
sess much  greater  value  for  a  specific  purpose  than 
another,  and  here  is  a  field  in  which  the  investigator 
mav  render  valuable  service. 


CHAPTER   XIII 

LAWS    OF  NUTRITION 

The  preceding  pages  have  been  devoted  to  a  discus- 
sion of  the  origin  of  cattle  foods,  what  they  are  in 
substance,  how  their  nutrients  are  made  available  and 
how  used.  So  far  no  attempt  has  been  made  to 
gather  together  in  a  systematic  relation  what  may  be 
called  the  fundamental  principles  or  laws  of  nutrition, 
some  of  which  we  have  not  yet  directly  stated,  but 
which  are  inferences  from  the  facts  presented.  It  is 
desirable  to  do  this,  however,  before  passing  to  the 
consideration  of   the  practice  of  cattle  feeding. 

1.  All  energy  and  building  material  applied  to  the 
maintenance  and  growth  of  the  animal  body  come 
from  the  food,  water  and  oxygen  being  included  in 
this  term.  The  animal  originates  neither  force  nor 
matter. 

2.  Only  that  portion  of  the  food  which  is  digested, 
i.  e.,  that  which  is  dissolved  by  the  digestive  fluids 
and  rendered  soluble  and  diffusible  so  that  it  passes 
into  the  blood,  is  available  for  any  use  whatever.  This 
fac{,  is  especially  important  in  view  of  the  greatly 
varying  digestibility  of  different  feeding  stuffs. 

3.  The  unutilized  food  and  the  wastes  pass  from  the 
body  in  some  direction.      The  undigested  part  mainly 

(182) 


Laws  of  Nutrition  183 

constitutes  the  solid  excrement  or  feces.  The  urea  and 
other  nitrogenous  compounds  which  are  the  unoxidized 
portion  of  the  protein,  pass  out  wholly  in  the  urine.  All 
digested  nitrogen  not  stored  is  found  here.  The  car- 
bon dioxid  is  eliminated  through  the  skin  and  lungs, 
chiefly  the  latter,  and  water  is  disposed  of  through 
the  kidneys,  skin  and  lungs. 

4.  The  digested  food  is  used  in  two  general  direc- 
tions, (a)  for  the  protection  of  energy  and  (h)  for 
constructive  purposes. 

(a)  The  food  energy  is  made  available  through 
combustion,  i.  e.,  the  burning  of  the  carbon  compounds 
of  the  food  to  simpler  substances,  carbon  dioxid  and 
water,  thus  liberating  the  energy  stored  in  the  plant 
during  its  growth.  Protein  is  never  fully  oxidized,  but 
carbohydrates  and  fats  may  be.  All  the  organic  nu- 
trients may  be  oxidized  to  produce  energy,  the  total  heat 
values  of  protein,  carboh^'drates  and  fats  being  approx- 
imately as  1.5,  1,  2.4.  This  liberated  energy  finds  ex- 
pression in  the  animal  organism  in  various  ways,  as  heat, 
mechanical  energy  or  motion  and  chemical  transforma- 
tions. The  total  energy  of  food  is  never  all  available  to 
the  animal  because  of  a  loss  in  the  excreta  and  gases. 
Moreover,  the  net  energy  gain  seems  not  to  be  propor- 
tional to  the  available  energy,  but  is  dependent  upon  the 
work  of  digestion,  which  varies  with  different  cattle  foods. 

(&)  The  food  compounds  are  used  for  constructive 
purposes,  either  without  changing  their  general  char- 
acter, as,  for  instance,  the  building  of  muscular  tissue 
from  the  plant  albuminoids,  or  they  may  be  reorgan- 
ized into  bodies  of  a  very  different  character,  as  in  the 


184  The  Feeding  of  Animals 

formation  of  animal  fats  from  starch  and  sugar.  Pro- 
tein is  used  to  construct  muscular  tissue,  in  fact,  all 
the  nitrogenous  parts,  and  it  is  perhaps  a  source  of 
fat.  Carbohydrates  can  only  be  used  constructively 
for  the  formation  of  fat,  and  the  same  is  true  of  food 
fats  or  oils.  Mineral  matter  is  needed  for  the  forma- 
tion of  bone  and  has  important  functions  in  digestion. 

5.  The  matter  of  the  digested  food,  including  water 
and  oxygen,  is  exactly  equal  to  that  stored  in  the  body 
or  in  milk,  or  both,  plus  that  in  waste  products, — feces, 
water,  carbonic  acid  and  urine  solids.  Such  a  balance 
may  not  be  maintained  for  any  particular  day,  but  will 
ultimately  be  found  to  exist. 

6.  Under  given  conditions  of  species,  sex,  climate 
and  use,  a  definite  amount  of  digested  organic  matter 
is  necessary  to  maintain  a  particular  animal  without 
gain  or  loss  of  body  substance.  This  means  simply 
that  tissue  wastes  must  be  replaced,  and  the  fuel  sup- 
ply must  be  kept  up. 

If  the  animal  receives  no  food,  or  less  than  the 
amount  needed  for  maintenance  purposes,  tissue  waste 
and  the  production  of  energ}^  do  not  cease,  but  go 
on  wholly  or  in  part  at  the  expense  of  the  body  sub- 
stance, and,  as  it  is  commonly  expressed,  the  animal 
"grows  thin." 

7.  Food  supplied  above  a  needed  maintenance  quan- 
tity may  be  utilized  for  the  production  of  new  sub- 
stances or  work  or  may  be  eliminated  in  part  and  increase 
the  waste.  Within  limits,  both  things  generallj'  occur. 
In  the  proper  sense  of  the  term,  no  production  ever 
occurs  without  an   excess   of   food   above  the   mainte- 


Laivs  of  Nutrition  185 

nance  requiremeut.  Milk  formation  maj"  sometimes 
go  on  at  the  expense  of  the  body  substance,  but  with 
proper  feeding,  milk,  flesh  or  muscular  work  are  pro- 
duced at  the  expense  of  food  supplied  in  excess  of  that 
needed  for  maintenance. 

8.  Regard  must  be  had  to  the  supply  of  particular 
nutrients  as  well  as  of  total  food.  Even  with  an  ani- 
mal doing  no  work  and  giving  no  milk  a  certain 
amount  of  protein  will  be  broken  up  constantly  into 
urea  and  similar  compounds,  an  amount  which  will  be 
withdrawn  from  the  body  tissues  to  the  extent  that  it 
is  not  supplied  by  the  food.  In  addition  to  this,  a  milch 
cow,  for  instance,  must  have  protein  for  the  formation 
of  the  nitrogen  compounds  of  the  milk,  or  a  steer  for 
the  growth  of  flesh  in  a  quantity  proportional  to  the 
production,  and  food  must  supply  it.  There  is,  there- 
fore, a  minimum  supply  of  protein,  which,  in  a  par- 
ticular case,  is  necessary  for  maintenance  and  for 
constructive  purposes,  less  than  which  ultimately  dimin- 
ishes production  to  the  extent  of  the  deficiency,  or  else 
requires  the  use  of  body  tissue. 

9.  The  different  classes  of  nutrients  are  to  some 
extent  interchangeable  in  their  functions.  That  is  to 
say,  all  the  organic  nutrients  may  be  burned  to  supply 
energy.  Protein  may  be  so  used  even  to  withdrawing 
it  from  the  purposes  to  which  it  is  necessary  unless 
the  carbohydrates  or  fats  are  sufficient  to  protect  it  from 
being  consumed  as  fuel.  A  proper  supply  of  the  non- 
nitrogenous  nutrients  is  required,  therefore,  to  insure 
the  application  of  the  necessary  minimum  of  food  pro- 
tein to  its  peculiar  uses. 


CHAPTER   XIV 

SOURCES    OF  KNOWLEDGE 

The  foregoing  chapters  embody  many  statements  of 
principles  and  facts  which  have  been  made  positively 
and  without  modification.  To  quite  an  extent  these 
are  based  upon  the  conclusions  of  scientific  men,  that 
is,  conclusions  which  have  been  reached  after  such  study 
of  the  problems  involved  as  is  competent  to  secure  ac- 
curate information.  In  some  cases  this  study  has  been 
severe  and  long  continued,  having  been  carried  on 
by  the  use  of  methods  and  apparatus  capable  of  the 
most  precise  measurements.  Moreover,  in  the  investi- 
gations of  science  an  effort  has  been  made  to  pro- 
ceed logically,  so  that  the  results  attained  shall  not 
be  fallacious.  Notwithstanding  the  fact  that  a  great 
deal  of  our  knowledge  is  the  result  of  an  earnest  and 
impartial  search  after  truth,  under  conditions  espe- 
cially favorable  to  its  discovery,  many  persons  are 
disposed  to  give  more  credit  to  the  traditions  and 
conclusions  of  practice  than  to  the  carefully  prepared 
verdicts  of  science.  It  may  not  be  out  of  place, 
therefore,  to  present  in  this  connection  some  of  the 
considerations  and  methods  which  have  to  do  with 
the  acquisition  of  knowledge  concerning  animal  nutri- 
tion, for   this  may  aid   us  to  appreciate  the  value  of 

(186) 


Ufal  Value  of  Practical  Observations  187 

well-established  facts  and  to  exercise  caution  in  ac- 
cepting the  verdicts  either  of  science  or  of  practice 
before  they  are  thoroughly  justified. 

There  are  three  general  ways  in  which  we  may  be 
said  to  have  acquired  knowledge  in  regard  to  feed- 
ing animals: 

1.  The  observation  of  ordinary  practice. 

2.  Practical  experiments,  so  called. 

3.  Scientific  investigation. 

CONCLUSIONS     OF     PRACTICE 

Until  within  recent  years,  the  practice  of  cattle- 
feeding  has  been  entirely  governed  by  the  conclu- 
sions drawn  from  ordinary  practice.  Among  the  many 
men  engaged  in  animal  husbandry,  certain  ones  pos- 
sessed of  more  than  average  powers  of  observation 
and  business  ability  have  secured  good  results  with 
certain  feeding  stuffs  and  methods  of  feeding,  and 
their  practice  has  been  accepted  by  their  neighbors 
with  no  further  demonstration  than  that  these  success- 
ful farmers  sold  fat  cattle  and  obtained  large  returns 
from  the  dairy.  During  the  centuries  that  man  has 
had  domestic  animals  under  his  care,  certain  results 
have  appeared  to  follow  from  certain  sj^stems  of  feed- 
ing or  the  use  of  certain  foods,  and  upon  these  so- 
called  practical  observations  the  feeder  has  built  his 
creed. 

In  these  ways  there  have  come  to  be  accepted, 
sometimes  locally  and  sometimes  generally,  standards 
of  feeding  as  to  quantity,  kind  of   ration,  and    times 


188  The  Feeding  of  Animals 

of  feeding.  At  the  same  time,  it  was  necessary  only  to 
attend  a  farmers'  convention  fifty  years  ago  to  become 
convinced  of  a  great  variety  of  opinions  as  to  the  best 
methods  of  practice.  In  fact,  opinion  was  the  court 
of  last  resort.  There  were  then  no  known,  well-estab- 
lished fundamentals  to  which  appeal  could  be  made  as 
a  basis  for  discussion.  While  many  false  notions  were 
entertained,  many  of  the  beliefs  then  prevailing  were 
undoubtedly  correct  or  contained  a  germ  of  truth.  It 
is  generally  safe  to  assume  that  when  an  opinion  is 
widely  and  persistently  held  it  is  not  altogether  with- 
out reason  or  foundation.  It  is  often  the  expression, 
in  more  or  less  correct  terms,  of  some  important  prin- 
ciple. No  one  should  lightly  turn  aside  from  the 
traditions  and  convictions  of  a  community  in  regard 
to  any  line  of  practice.  A  knowledge  of  the  precepts 
governing  the  feeder's  art  that  are  the  accumulation 
of  experience  in  the  care  of  animals  is  to  be  respected 
and  is,  to  a  great  extent,  essential  to  successful  prac- 
tice. It  is  also  true  that  little  substantial  progress 
can  be  realized  in  any  art  if  its  underlyiug  truths  are 
not  understood,  for  when  this  is  the  case  the  results 
of  experience  under  one  set  of  conditions  do  not  serve 
as  a  guide  under  circumstances  entirely  different. 

PRACTICAL     FEEDING     EXPERIMENTS 

With  the  advent  of  modern  science  and  of  the 
efforts  to  utilize  it  in  agriculture,  an  attempt  has  been 
made  to  search  for  important  truths  more  systematically, 
an  effort  undertaken  chiefly  by  experiment  stations.    As 


Insufficiency   of  Some  Experiments  189 

one  means  of  gaming  knowledge,  these  institutions, 
and  to  some  extent  private  farmers,  have  conducted 
many  so-called  practical  feeding  experiments  in  order 
to  verify  present  beliefs,  test  theories  and  solve  exist- 
ing problems.  The  relative  value  of  various  feeding 
stuffs  and  rations  for  producing  growth  and  milk  and 
the  influence  of  different  fodders  and  grain  foods  upon 
the  quality  of  the  product  have  been  the  subjects  of 
numerous  feeding  tests.  Much  valuable  information 
has  been  secured  in  this  way,  but  there  has  not 
always  been  a  full  recognition,  even  by  experiment 
stations,  of  the  limitations  which  should  be  observed 
in  drawing  conclusions  from  this  manner  of  experi- 
mentation. 

In  order  to  view  this  matter  more  in  detail,  let  us 
consider  experiments  in  testing  rations  for  growth  and 
milk  production.  The  usual  method  of  procedure  with 
such  feeding  trials  is  either  to  feed  two  lots  of  animals 
on  the  rations  to  be  compared  and  note  the  comparative 
growth  or  milk  yield,  or  to  feed  the  same  lot  on  one 
ration  for  a   time  and  then  change  to  another  ration. 

If  these  tests  are  made  with  growing  or  fattening 
animals,  the  increase  in  live  weight  is  taken  as  the 
measure  of  the  relative  efficiency  of  the  rations  com- 
pared. It  should  be  said  of  these  experiments  that 
their  apparent  verdict  is  to  be  accepted  with  great 
caution,  and  definite  conclusions  are  not  justified  until 
repeated  trials  of  two  rations  or  of  two  systems  of 
feeding,  made  with  the  use  of  all  possible  precautions 
against  error,  and  under  a  variety  of  conditions,  give 
uniform  and  consistent  results   in  the  same  direction. 


190  The  Feeding  of  Animals 

There  are  several  reasons  why  this  is  so,  the  main  one 
being  that  the  increase  in  the  weight  of  an  animal  is  an 
uncertain  measure  of  actual  growth.  Variations  in  the 
contents  of  the  alimentary  canal  due  to  the  irregular- 
ity of  fecal  discharge  and  to  a  lack  of  uniformity  in 
the  water  drank  may  cause  temporary  variations  in  the 
live  weight  of  considerable  magnitude.  Moreover,  the 
nature  of  the  growth  of  body  substance  is  revealed  by 
neither  the  mere  weighing  of  an  animal  nor  by  his 
general  appearance.  Even  if  the  changes  in  weight  are 
due  to  an  increase  of  body  tissue,  this  may  be  more 
largely  water  in  one  case  than  in  another,  so  that  the 
real  contribution  of  the  food  to  the  dry  substance  of 
the  body  may  not  be  shown.  Nor  is  the  character  of 
the  solids  deposited  in  the  animal  discovered  by  merely 
weighing  him.  In  fact,  by  such  practical  experiments 
we  simply  learn  that  one  set  of  animals  has  gained 
more  or  less  pounds  of  weight  than  another  set,  but 
the  why  and  the  how  are  not  explained. 

Practically  the  same  considerations  pertain  to  feed- 
ing tests  for  milk  production.  When  the  milk  flow 
from  one  ration  is  larger  than  from  another,  we  can 
easily  satisfy  ourselves  as  to  the  comparative  yield  of 
milk  solids,  which  is  the  real  test  of  such  production; 
but  we  are  not  able  to  decide  whether  the  cow  either 
may  not  have  contributed  to  the  milk  secretion  from 
the  substance  of  her  own  body,  or  may  not  have  gained- 
in  body  substance,  the  extent  of  such  loss  or  gain 
being  greater,  perhaps,  with  one  ration  than  with 
another. 

Even  if  these  uncertainties  did  not  exist,  we  have 


Development  of  Necessary   Knowledge  191 

the  still  greater  disadvantage  of  not  learning  by  this 
means  why  a  particular  combination  of  feeds  has 
superior  qualities  for  causing  growth  or  sustaining 
milk  secretion.  The  mere  data  showing  that  an  ani- 
mal ate  so  many  pounds  of  food  and  produced  so 
many  pounds  of  beef  or  milk  are  important  business 
facts,  but  they  reveal  nothing  concerning  the  uses  of 
the  several  classes  of  nutrients  and  of  themselves  fur- 
nish slight  basis  for  developing  a  rational  system  of 
feeding.  We  must  somehow  learn  the  function  of  pro- 
tein, carbohydrates  and  fats  in  maintaining  the  various 
classes  of  animals  and  the  real  effect  of  varying  the 
source,  quantity  and  relative  proportions  of  these  nutri- 
ents before  we  can  draw  safe  general  conclusions. 

CHEMICAL    AND    PHYSIOLOGICAL     STUDIES 

As  preliminary  to  more  comprehensive  and  convinc- 
ing methods  of  investigating  feeding  problems,  there 
has  been  going  on  during  many  years  a  necessarj^  study 
of  the  compounds  which  are  found  in  plants  and  ani- 
mals. Much  has  been  learned  about  the  ultimate  com- 
position and  the  constitution  of  the  albuminoids,  carbo- 
hydrates and  fats,  their  physical  and  chemical  proper- 
ties, the  compounds  into  which  these  bodies  break 
under  certain  conditions,  the  chemical  changes  to 
which  they  are  subject  through  certain  agencies,  and 
their  relation  to  one  another.  Investigations  along 
these  lines  have  for  j^ears  occupied  the  time  of  some 
of  our  ablest  scientists,  and,  while  such  researches  when 
they  were  conducted  may  have  seemed  to  the  extreme 


192  The  Feeding  of  Animals 

utilitarian  to  be  of  little  value,  we  now  see  how  di- 
rectly they  are  contributing  to  human  progress  and 
welfare. 

To  the  above  information  has  been  added  through 
physiological  investigations  a  knowledge  of  the  ways 
in  which  the  several  food  compounds  are  transformed 
in  digestion  and  in  other  metabolic  changes,  the 
avenues  along  which  these  compounds  travel,  and  the 
ways  in  which  their  products  of  decomposition  are  dis- 
charged from  the  animal  organism.  We  have  learned 
how  to  distinguish  between  the  digested  and  undi- 
gested food,  have  demonstrated  that  all  the  nitrogen 
of  the  decomposed  proteids  passes  oif  in  the  urine, 
have  measured  the  combustion  of  the  nutrients  and 
have  learned  how  to  strike  a  balance  between  the  in- 
come and  outgo  of  the  animal  body.  It  is  now  possi- 
ble to  determine  with  reasonable  accuracy  just  how 
much  substance  is  retained  or  lost  from  the  body  of 
the  experimental  animal  while  eating  a  given  ration,  and 
what  is  the  nature  of  the  gain  or  loss.  Very  recently 
means  have  also  been  devised  for  measuring  the  heat 
given  off  by  a  man  or  an  animal  in  order  to  ascertain 
the  actual  physiological  values  of  different  feeding 
stuffs. 

MORE  ACCURATE  METHODS  OP  INVESTIGATION 

In  applying  the  principles  and  facts  of  chemistry 
and  physiology,  the  first  advance  from  the  ultra -prac- 
tical feeding  experiment  in  the  direction  of  an  accurate 
history  of  wliat  occurs   when    the    animal  is  eating    a 


Progress  in  Experimental  Methods  193 

particular  ration  is  the  measurement  of  the  digested 
nutrients  and  the  determination  of  the  gain  or  loss  of 
nitrogen.  This  is  accomplished,  as  heretofore  stated,  by 
ascertaining  the  quantity  of  various  compounds  eaten 
and  the  amount  of  the  same  in  the  feces,  the  differ- 
ence being  the  digested  portion.  The  urine  is  also 
collected,  and  if  the  nitrogen  in  it  is  less  or  more 
than  that  in  the  digested  protein,  then  the  animal  is 
either  gaining  or  losing  nitrogenous  body  substance, 
unless  the  measurement  is  with  a  milch  cow,  when  the 
nitrogen  in  the  milk  must  be  taken  into  account.  By 
an  experiment  conducted  in  this  way,  with  careful  and 
continued  weighings  of  the  experimental  animal,  it  is 
possible  to  secure  a  probable  relation  between  a  unit 
of  digested  dry  matter  and  a  unit  of  production.  Such 
a  method  has  been  used  to  determine  what  is  a  main- 
tenance ration  for  animals  of  several  classes,  and  in 
those  cases  where  the  experiments  have  been  continued 
for  a  sufficient  length  of  time  and  have  shown  on 
repetition  a  reasonable  agreement,  we  are  justified  in 
accepting  the  results  as  a  close  approximation  to  fact. 
When  a  ration  keeps  an  animal  in  nitrogen  equilibrium 
for  one  or  more  months  and  no  material  gain  or  loss 
of  weight  occurs,  we  may  safely  regard  it  as  approxi- 
mately a  maintenance  ration  under  the  conditions  in- 
volved. Experiments  of  the  same  kind  are  equally 
useful  in  testing  the  productive  power  of  various  food 
combinations,  and  whenever  by  such  continued  tests 
one  ration  shows  no  superiority  over  another,  it  is 
safe  to  assume  that  no  differences  exist  which  would 
be  especially  important  to  the  farmer's  pocketbook. 

M 


194  The  Feeding  of  Animals 

RELATION  OF  FOOD  TO  PRODUCTION 

Another  class  of  experiments  somewhat  more  severe 
in  their  requirements  are  those  designed  to  give  infor- 
mation as  to  the  relation  between  the  constituents  of 
the  food  and  the  growth  of  the  various  tissues  in  the 
animal  body  or  the  formation  of  milk  solids.  The  ex- 
periments conducted  by  Lawes  and  Gilbert  on  the  for- 
mation of  fat  with  swine  may  be  cited  in  illustration  of 
the  methods  used.  These  were  planned  so  as  to  learn 
the  amounts  of  digested  protein,  carbohydrates  and 
fat  consumed  by  the  animal  and  also  the  quantities  of 
protein  and  fat  stored  in  the  body  during  a  given 
period.  "In  experiment  No.  1,  two  pigs  of  the  same 
litter,  of  almost  exactly  equal  weight,  and,  so  far  as 
could  be  judged  of  similar  character,  were  selected." 
One  was  killed  at  once  and  its  composition  determined, 
and  the  other  was  fed  for  ten  weeks  on  a  fattening 
ration  of  known  composition  and  then  slaughtered  and 
analyzed.  The  quantity  of  protein  and  fat  which  the 
pig's  body  had  gained  during  the  ten  weeks  as  ascer- 
tained from  the  composition  and  weight  of  the  two 
pigs  was  then  compared  with  the  food  supply  of  simi- 
lar compounds.  It  was  assumed  that  a  pound  of  food 
fat  could  produce  a  pound  of  body  fat  and  that  51.4 
per  cent  of  all  the  protein  not  stored  in  the  body 
as  such  could  be  used  for  fat  formation.  Even  with- 
the  most  liberal  allowances  it  was  found  that  the  pro- 
tein and  fat  of  the  food  could  not  possibly  have  been 
the  sole  source  of  tlie  ncAv  body  fat,  thus  forcing  the 
conclusion    that    the    carbohydi-ates    are    fat -formers. 


Experiments   on    Use   of  Nutrients  195 

Practicall}^  the  same  plan  has  been  followed  in  study- 
ing the  source  of  milk  fat.  Several  cows  were  fed  on 
carefully  weighed  and  analj'zed  rations  extremely  poor 
in  fat,  and  the  amount  and  composition  of  the  feces, 
urine  and  milk  were  ascertained  during  sixty  to  ninety 
days.  The  fat  digested  from  the  food  and  the  theo- 
retical fat  equivalent  of  the  decomposed  protein  as 
measured  by  the  urine  nitrogen  were  charged  up 
against  the  milk  fat,  and  a  large  quantity  of  the  lat- 
ter could  be  accounted  for  only  as  having  had  its 
source  in  carbohydrates. 

Another  method  of  investigating  fat  formation  has 
been  used  with  dogs.  It  is  well  known  that  when  an 
animal  is  deprived  of  food  the  expenditure  of  energy 
by  the  body  is  maintained  at  the  expense  of  body  sub- 
stance. Both  muscular  tissues  aud  fatty  substance  are 
broken  down  and  used  in  this  way,  the  latter  being 
regarded  as  furnishing  the  most  natural  and  available 
supply  of  fuel.  It  was  found  in  the  case  of  dogs  that 
after  a  certain  number  of  days  of  starvation  there  oc- 
curred a  sudden  and  large  increase  in  the  waste  of 
nitrogen  compounds  as  shown  by  the  urine  excretion, 
the  explanation  for  this  being  that  the  body  fat  had 
become  exhausted  and  a  demand  was  at  once  made  upon 
the  proteid  tissues  for  the  necessary  supply  of  energy. 
As  soon  as  this  rise  of  nitrogen  waste  appeared,  then  the 
dog  was  allowed  to  eat,  and  whatever  fat  was  found  in 
the  body  at  the  end  of  the  feeding  period  was  regarded 
as  having  been  formed  from  the  food  taken  after  the 
starvation  period.  If,  for  instance,  the  ration  was 
wholly  protein  and  fat  was  found  to  have  become  de- 


196  The  Feeding  of  Animals 

posited  in  the  body,  this  was  regarded  as  proof  of  the 
formation  of  fat  from  protein.  Such  experiments  as 
these  have  not  always  been  conclusive,  although  they 
are  regarded  by  some  scientists  as  having  furnished 
proof  that  protein  may  be  a  source  of  fat. 

THE   RESPIRATION   APPARATUS 

After  all,  the  investigations  of  the  kinds  described 
fail  to  furnish  data  so  accurate  and  so  complete  as  are 
necessary  for  entirely  safe  conclusions.  In  every  in- 
stance, one  or  more  assumptions  are  involved  where 
definite  proof  is  not  furnished.  Nothing  short  of  a 
complete  record  of  the  income  and  outgo  of  the  ani- 
mal organism  during  the  experimental  period  is  con- 
clusive evidence  as  to  whether  there  has  been  a  gain 
or  loss  of  body  substance  and  what  is  the  kind  and 
extent  of  the  growth  or  waste.  The  securing  of  such 
a  record  is  an  expensive  and  laborious  task.  It  re- 
quires not  only  complete  information  in  regard  to  the 
quantity  and  composition  of  the  food,  but  also  an  ac- 
curate measurement  of  the  excreta,  including  the  feces, 
the  urine,  the  respiratory  products  and  the  matter 
given  off  through  the  skin.  Such  measurements  are 
taken  by  means  of  a  respiration  apparatus,  a  costly 
and  complicated  mechanism,  a  detailed  description  of 
which  would  be  of  little  use  to  most  readers.  It  is 
sufficient  to  state  that  this  apparatus  makes  possible 
the  collection  and  analysis  of  all  the  excretory  products, 
whether  solid  or  gaseous.  The  experimental  man  or 
animal  lives  in  a  closed  chamber  into  which  is  intro- 


Investigation  with  Respiration  Apparatus       197 

duced  food  and  fresh  air  and  from  which  is  pumped 
the  vitiated  air,  the  water  and  carbon  dioxid  of  which 
are  absorbed  and  weighed. 

All  conclusions  drawn  from  experiments  with  the 
respiration  apparatus  are  based  largely  upon  the  in- 
come and  outgo  of  nitrogen  and  carbon.  As  carbon 
is  a  constituent  of  all  possible  compounds  of  the  ani- 
mal body  except  the  mineral,  it  is  certain  that  when 
the  body  gains  in  carbon  it  gains  in  organic  sub- 
stance of  some  kind,  and  if  it  loses  in  carbon  there 
is  a  waste  of  organic  body  substance.  The  general 
character  of  the  gain  or  loss  can  be  determined  by  the 
nitrogen  balance.  If  more  nitrogen  is  taken  in  by  the 
experimental  animal  than  is  given  off,  it  is  clear  that 
the  nitrogen  compounds  of  the  body  have  received  an 
accession.  Knowing  as  we  do  the  proportions  of  nitro- 
gen and  carbon  in  the  various  tissues  of  the  animal, 
we  can  calculate  how  much  of  the  gain  or  loss  of 
carbon  belongs  in  the  nitrogenous  substance  deposited 
or  wasted.  If  more  carbon  is  gained  or  lost  than  can 
possibly  be  associated  with  the  nitrogen  gained  or  lost, 
then  there  has  been  a  gain  or  loss  of  fat,  because  protein 
and  fat  being  the  main  constituents  of  the  animal  car- 
cass, any  considerable  retention  of  carbon  must  be  in  one 
of  these  forms.  If  there  has  been  nitrogen  equilibrium, 
all  excess  or  deficit  of  carbon  belongs  to  a  deposit  or 
waste  of  fat.  By  such  searching  methods  as  these,  it 
is  possible  to  ascertain  with  a  good  degree  of  accuracy 
how  food  is  used  and  what  quantity  and  kind  of  nu- 
trients are  needed  in  maintaining  an  animal  under 
given  conditions. 


198  The  Feeding  of  Animals 

DETERMINATION  OF  ENERGY  VALUES 

We  have  reached  a  point  in  our  study  of  animal 
nutrition  where  we  realize  that  food  values  are  to 
some  extent  commensurable  with  energy  values  and 
that  it  is  desirable  to  know  the  energy  product  of 
different  compounds  and  feeding  stuffs.  Moreover,  we 
cannot  possess  sufficiently  full  knowledge  concerning 
the  energy  needs  of  the  several  classes  of  animals 
until  we  have  measured  energy  consumption  under 
the  various  conditions  of  work  and  of  production. 
The  mere  determination  of  the  income  and  outgo  of 
the  animal  body  does  not  necessarily  measure  energy 
needs  or  use.  We  may  go  so  far  as  to  ascertain  that 
a  certain  amount  of  carbon  from  a  certain  source 
was  consumed  in  a  given  time,  but  from  this  alone  we 
do  not  learn  the  extent  to  which  this  combustion  has 
supported  the  internal  and  external  work  of  the  body. 

Calculation  of  the  energy  value  of  a  ration. —  Three 
methods  may  be  adopted  for  determining  the  energy 
expenditure  by  an  animal  eating  a  given  ration.  The 
one  of  these  most  easilj"  carried  out  is  largely  a 
matter  of  mathematical  calculation.  By  the  use  of 
average  digestion  coefficients  it  is  possible  to  ascer- 
tain approximately  the  amounts  of  digestible  protein, 
carbohydrates  and  fats  contained  in  any  ration  which 
is  apparently  accomplishing  a  desired  result.  We  know 
from  previous  determinations  what  are  the  calorific 
values  of  individual  compounds  such  as  albumin, 
starch,  sugar,  stearin  and  olein,  and  these  compounds 
are    assumed    to    represent    the    energy   value   of    the 


Establishing   Energy    Values  199 

classes  of  nutrients  to  which  they  belong.  If,  then, 
we  multiply  the  calculated  quantities  of  digestible  pro- 
tein, carbohydrates  and  fats  by  their  respective  as- 
sumed energy  factors,  we  get  a  number  which  may  be 
taken  as  an  expression  of  the  available  energy  of  the 
ration  under  consideration.  This  method  cannot  be 
regarded  as  entirely  accurate,  because  the  calorific  value 
for  protein  may  not  be  the  same  as  that  for  any  single 
albuminoid,  and  the  heat  units  of  the  nitrogen-free 
extract  are  likely  to  vary  materially  from  those  found 
for  the  starches  and  sugars,  while  the  ether  extract  is 
very  far  from  representing  the  pure  fats.  At  the  same 
time,  it  is  possible  in  this  way  to  learn  the  energy 
value  of  a  ration  closely  enough,  perhaps,  for  all  prac- 
tical purposes. 

Energy  value  of  digested  nutrients.  —  A  second 
method,  which  is  probably  a  step  in  the  direction 
of  greater  accuracy,  is  to  determine  by  the  use  of 
a  calorimeter  the  heat  units  of  the  ration  and  also 
of  the  urine  and  feces.  The  differences  between  the 
food  heat  units  and  those  found  for  the  excreta  are 
assumed  to  represent  the  energy  value  of  that  por- 
tion of  the  ration  appropriated  by  the  animal.  Pro- 
vided the  heat  units  obtained  in  calorimeter  combus- 
tion and  physiological  combustion  are  equivalent,  this 
method  must  be  considered  as  furnishing  a  reliable 
energy  measurement.  However  probable  this  equivalence 
may  seem,  it  has  not  been  fully  demonstrated.  We 
still  need  more  complete  experimental  proof  that  the 
oxidation  of  the  several  food  compounds  in  ordinary 
combustion  and   in  the  animal    produces  identical  re- 


200  The  Feeding  of  Animals 

suits  in  the  two  cases.  Even  if  this  method  gives 
us  a  correct  estimation  of  the  energy  equivalent  of 
the  food  used,  it  furnishes  no  definite  iuformation  as 
to  the  manner  of  use.  It  does  not  appear  to  what  ex- 
tent the  digested  nutrients  have  been  oxidized  with  a 
corresponding  radiation  of  heat  or  whether  there  has 
been  a  gain  or  loss  of  body  substance.  If  there  has 
been  a  gain  of  body  substance,  then  the  needs  of  the 
work  horse  or  milch  cow,  if  these  are  under  considera- 
tion, are  less  than  the  heat  units  of  the  ration,  but  if 
there  has  been  a  loss  of  body  substance,  then  the 
ration  is  below  the  required  standard  for  the  par- 
ticular animal  under  investigation.  In  a  study  of 
energy  relations,  it  is  therefore  even  more  necessary  to 
resort  to  a  respiration  apparatus  of  some  sort  than  in 
determining  food  balances.  We  must  learn  the  actual 
extent  of  the  food  combustion  which  occurs  if  we 
would  have  all  the  data  necessary  for  measuring  energy 
used,  and  here  we  come  to  the  third  and  most  accu- 
rate method  of  determining  energy  expenditure;  viz., 
experiments  with  a  respiration  apparatus. 

Measurement  of  food  comhustion. — There  are  two 
general  ways  of  ascertaining  the  extent  to  which 
food  is  burned  by  any  living  organism.  One  is  to 
measure  the  products  of  combustion  and  the  other 
is  to  measure  the  amount  of  oxygen  used.  It  is  self- 
evident  that  no  combustion  can  occur  without  the 
use  of  oxygen,  and  so  if  the  experimenter  is  able  to 
learn  just  how  nuich  of  this  element  is  taken  up  in 
uniting  with  the  carbon  and  hydrogen  of  the  food,  he 
has  a  direct  and  accurate  means  of  measuring  actual 


Respiration   Calorimeter  201 

energy  production.  The  older  forms  of  respiration  ap- 
paratuses simply  allowed  an  estimation  of  the  carbon 
dioxid  and  water  given  off  by  the  animal.  How  much 
of  the  water  was  formed  by  the  oxidation  of  the 
hydrogen  of  the  food  and  how  much  was  simply  evapo- 
rated from  the  store  taken  in  as  water,  it  was  impos- 
sible to  know  by  direct  determination.  This  could 
only  be  calculated.  The  carbon  dioxid  was,  on  the 
other  hand,  a  direct  and  accurate  measure  of  the  com- 
bustion of  carbon.  Later  devices,  as,  for  instance,  the 
one  used  by  Zuntz,  allow  a  direct  determination,  not 
only  of  the  products  of  combustion,  but  of  the  oxygen 
absorbed  by  breathing.  This  method  of  work  has 
great  advantages,  as  one  measurement  not  only  checks 
the  other,  but  makes  it  possible  to  ascertain  the  actual 
oxygen  consumption  during  any  given  period  of  the 
experiment,  as,  for  instance,  when  the  animal  is  at 
rest,  when  masticating  food,  or  when  performing  a 
given  amount  of  external  work.  In  this  way,  Zuntz 
made  his  masterly  demonstrations  of  the  differences 
in  the  net  values  of  different  foods  due  to  the  greater 
energy  cost  of  masticating  and  digesting  certain  ones. 
Respiration  calorimeter. — None  of  the  older  appara- 
tuses, whether  allowing  the  determination  of  oxygen 
consumption  or  not,  measured  the  heat  radiation  from 
the  animal  body,  or,  in  other  words,  the  amount  of 
energy  actually  evolved  from  internal  combustion. 
Recently  Professors  Atwater  and  Rosa  have  devised  a 
respiration  apparatus  which  is  at  the  same  time  a  cal- 
orimeter. The  quantity  of  heat  radiated  from  a  man 
or  other  animal  confined  in  this  calorimeter  is  absorbed 


202  The  Feeding  of  Animals 

by  a  known  volume  of  water  and  is  thus  determined. 
This  is  a  great  advance  towards  certainty,  because 
direct  measurements  of  the  energy  of  a  ration  in  use 
are  thus  made  possible  and  the  necessity  for  theoreti- 
cal assumptions  is  largely  removed. 

It  is  already  made  clear  to  the  reader,  doubtless, 
that  the  demonstration  of  facts  and  principles  in  the 
domain  of  animal  nutrition  is  exceedingly  difficult.  It 
should  be  equally  clear  that  when  conclusions  .  are 
reached  in  ways  which  have  been  briefly  described, 
they  are  worthy  of  respect  and  should  have  greater 
weight  than  the  necessarily  imperfect  observations  of 
common  practice.  Science  often  errs  in  her  deduc- 
tions, but  the  efforts  of  her  workers  are  constantly 
directed  towards  the  elimination  of  false  conclusions, 
so  that  unsound  theories  are  not  likely  to  be  accepted 
for  a  great  length  of  time. 


PAUT  II— THE  PBACTICE   OF  FEEDING 
CHAPTER   XV 

CATTLE   FOODS  — NATURAL  PRODUCTS 

The  number  of  cattle  foods  now  available  for  use 
is  very  large,  and  the  list  appears  to  be  constantly 
increasing.  Not  only  have  several  fodder  plants  been 
added  to  those  formerly  grown,  bnt  we  have  now  a  great 
variety  of  waste  products  from  the  manufacture  of  oils, 
starch,  and  human  foods  that  are  being  placed  upon 
the  market  as  feeding  stuffs.  At  one  time  farmers 
produced  all  their  cattle  ate,  and  this  was  done  without 
going  outside  a  very  limited  list  of  forage  plants  and 
grains.  All  this  is  changed,  especiallj^  in  the  older, 
more  thickly -settled  portions  of  the  United  States,  so 
that  considerable  knowledge  is  now  needed  regarding 
the  composition  and  specific  characters  of  the  numerous 
kinds  of  feeding  stuffs  if  they  are  to  be  used  intel- 
ligenth'. 

It  will  aid  in  discussing  this  branch  of  our  subject 
if  we  first  note  the  divisions  into  which  the  materials 
used  for  feeding  farm  animals  are  grouped.  There  is 
more  than  one  basis  upon  which  it  is  possible  to  make 
these  divisions, — botanical  relations,  the  portion  of  the 
plant  used,  whether  stem  or  fruit,  and  chemical  com- 
position.     As   a    matter   of  fact,   all   these   and   other 

(203) 


204  The  Feeding  of  Animals 

distinctions    are   involved   in   the   classification    of   the 
cattle  foods  in  common  use  at  the  present  time. 

The  feeding  stuffs  of  vegetable  origin  are  generally 
divided  into  four  classes:  (1)  forage  crops,  consisting 
of  the  stem  and  leaves  of  herbaceous  plants,  either  in 
green  or  air -dry  condition,  to  which  is  attached  in  some 
cases  the  partially  formed  or  wholly  mature  seed  or 
grain;  (2)  roots  and  tubers,  or  the  thickened  under- 
ground portions  of  certain  plants;  (3)  seeds  or  grains; 
(4)  parts  of  seeds  or  grains  which  are  the  by-products 
from  the  removal  of  other  parts  by  some  manufacturing 
process.  These  are  the  commercial  by-product  feeding 
stuffs. 

FORAGE  CROPS 

The  valuable  forage  plants  of  the  United  States 
belong  mostly  to  two  families,  the  grasses  (gramineae) 
and  the  legumes  (leguminosfe) .  June  grass,  red  top, 
timothy  and  the  cereal  grain  plants  are  types  of  the 
former;  and  the  clovers,  alfalfa  (Fig.  3),  the  vetches, 
and  peas,  of  the  latter.  Whether  in  the  pasture  or  in 
tilled  fields,  few  plants  outside  of  these  divisions  con- 
tribute materially  to  the  supply  of  high -class  fodders. 
The  most  essential  difference  between  the  members  of 
these  two  families  of  plants  when  considered  as  feeding 
stuffs  is  the  larger  proportion  of  nitrogen  compounds 
in  the  legumes.  It  is  characteristic  of  all  legumes  that 
their  proportion  of  protein  is  high  as  compared  with 
any  other  forage  crops,  and  for  this  reason  they  are 
greatly  prized  on  dairy  farms.  The  fact  that  they  are 
regarded  as  increasing  materially  the  nitrogen  supply 


Influence  of  Drying  Fodders 


205 


of   the  farm   from  sources  outside  the   soil    also   adds 
to  their  value. 

Green  vs.  dried  fodders.  —  Conditions  of  drying.  — 
Nearly  all  of  the  herbaceous  plants  that  are  growu  for 
consumptiou  by  farm  animals  may  be  fed  either  in  a 
green  or  dry  state.  Oats,  maize,  clover,  alfalfa,  and 
other  species  which  serve  so  useful  a  purpose  as  soil- 
ing crops  for  summer  feeding  are  also  dried  that  they 
may  be  successfully  stored  for  winter  feeding,  though 


Fig.  'S.    Crop  of  alfalfa,  New  York  State  Experiment  Station. 

maize,  and,  to  some  extent,  other  crops,  are  now  pre- 
served in  a  green  condition  through  the  process  of 
ensilage. 

The  advantages  and  disadvantages  of  green  as  com- 
pared with  dry  fodders  have  been  much  discussed,  and 
some  of  the  facts,  chemical  and  otherwise,  bearing 
upon  the  ciuestion  are  presented  in  this  connection.  It 
is  safe  to  assert  that  the  compounds  of  a  dried  fodder 
which  has  suffered  no  fermentation  are  practically  what 
they  were  in  the  green,  freshly-cut  material,  excepting 
that    nearly  all  of   the  water  contained   in   the   green 


206  The  Feeding  of  Animals 

tissues  has  evaporated  and  that  in  drying  there  is  a 
possible  loss  of  an  imperceptible  amount  of  volatile 
compounds,  vv^hose  presence  in  the  plant  aifects  its 
flavor  more  or  less.  It  is  certain  that  curing  a  plant 
generally  diminishes  its  palatableness  and  increases  its 
toughness,  or  its  resistance  to  mastication,  although 
with  many  crops,  as  for  instance  the  early -cut  native 
grasses,  these  changes  do  not  affect  nutritive  value  to 
a  material  extent.  There  is  no  question  but  that  the 
mere  matter  of  being  green  or  being  dry  has  very  little 
influence  upon  the  heat  which  a  fodder  will  develop 
when  burned  or  upon  the  extent  to  which  it  will 
sustain  growth  or  milk  formation.  We  must,  how- 
ever, take  into  account  the  desirability  of  the  highest 
state  of  palatableness. 

It  is  a  fact  that  drying  fodders  under  perfect  con- 
ditions is  often  not  possible.  The  long -continued  and 
slow  curing  of  grass  in  cloudy  weather,  especially  when 
there  is  more  or  less  rainfall,  is  accompanied  by  fer- 
mentations that  result  in  a  loss  of  dry  substance 
more  or  less  extensive,  and  which  involve  some  of 
the  most  valuable  compounds,  principally  the  sugars. 
The  tissues  of  certain  plants,  maize  for  instance,  are 
so  thick  that  rapid  curing  in  the  field  is  never  pos- 
sible, and  fermentative  changes  are  unavoidable.  It  is 
probable  that  maize  fodder  and  stover  are  never  field- 
dried  without  a  material  loss  in  food  value,  for  the 
chemist  finds  that  even  when  the  stalks  are  finely 
chopped,  drying  by  artificial  heat  is  necessary  to  a 
complete  retention  of  the  dry  matter.  The  extent  of 
the   loss   from  curing  fodders  must   be  very  variable. 


Conditions  of  Curing  Fodder  207 

So  far  as  we  know,  grass,  which  in  "good  haying 
weather"  is  well  stirred  during  the  day  and  packed 
into  cocks  over  night  so  as  to  avoid  the  action  of 
heavy  dew,  suffers  practically  no  deterioration,  while 
dull  weather  or  rain  may  cause  a  serious  loss.  It  is 
doubtful,  however,  whether  night  exposure  during  good 
weather  is  sufficiently  injurious  to  justify  the  expense 
of  cocking  partially  cured  hay.  On  the  other  hand, 
the  economy  of  using  hay  caps  during  unfavorable 
weather  is  without  question.  The  over -drying  of  hay 
before  raking  into  winrows  and  "bunching "  so  as  to 
cause  a  loss  of  the  leaves  and  the  finer  parts-  through 
brittleness  may  be  as  wasteful  as  under -drying  and 
the  consequent  fermentation.  Over -dried  hay  does 
not  pack  well  in  the  mow  and  is  less  palatable.  The 
leguminous  hays,  such  as  clover  and  alfalfa,  are  es- 
pecially subject  to  loss  from  over -drying  before  han- 
dling. Fodder  crops,  if  dried  at  all,  should  be  dried 
to  such  a  per  cent  of  moisture  that  they  will  not 
"  heat "  to  discoloration  after  being  packed  in  large 
masses  and  lose  dry  matter  from  the  same  general 
causes  that  operate  in  field  -  curing  under  bad  con- 
ditions. 

The  harvesting  of  forage  crops.  —  The  result  to  be 
achieved  in  the  growing  of  forage  crops  is  the  produc- 
tion on  a  given  area  of  the  maximum  quantity  of  di- 
gestible food  materials  in  a  palatable  form.  The  age 
or  period  of  growth  at  which  a  forage  crop  is  harvested 
is  an  important  factor  in  this  relation  and  may  affect 
the  product  in  three  ways:  (1)  in  the  quantity  of  ma- 
terial   harvested,    (2)   in  the  composition  of  the  crop, 


208  The  Feeding  of  Animals 

and  (3)  in  the  palatableness  of  the  resulting  fodder. 
In  discussing  this  question  we  must  recognize  the  fact, 
first  of  all,  that  in  these  respects  no  general  conclusion 
is  applicable  to  all  crops.  What  would  be  wisest  in 
the  management  of  the  meadow  grasses  might  be 
wasteful  in  handling  the  legumes,  and  especiall}^  so  in 
harvesting  maize. 

The  truth  of  this  statement  will  appear  as  the  facts 
are  displayed. 

It  is  safe  to  assert  that  in  general  the  maximum 
quantity  of  dry  matter  is  secured  when  forage  crops 
are  allowed  to  fully  mature  and  ripen.  The  only 
exception  to  the  rule  is  found  in  the  legumes  such  as 
the  clovers  and  alfalfa,  where  at  maturity  the  leaves 
unavoidably  rattle  off  and  are  lost,  either  before  or 
during  the  process  of  curing.  The  fact  that  growth  of 
dry  matter  takes  place  up  to  the  time  of  full  maturity  is 
well  illustrated  by  the  results  of  experiments  conducted 
on  the  farms  of  the  Pennsylvania  State  College,  the 
New  York  Experiment  Station,  and  the  University  of 
Maine,  in  cutting  timothy  grass,  clover,  and  maize  at 
different  stages  of  growth.  These  results  are  sum- 
marized in  the  accompanying  tables: 

Timothy  grass  (yield  of  dry  hay  per  acre) 

Results  in  Pennsyl- 
^— Results  in  Maine-^        vania— two  farms 
av.  3  years       1  year  av.  2  years 

1878-1880  1889  1881-1882 

Stage  of  growth  lbs.  lbs.  lbs. 

Nearly  in  head 3,720 

Full  bloom 4,072        4,225  2,955 

Out  of  bloom  or  nearly  ripe  .  4,136        5.086  3,501 

Kipe ,  a,832 


Influence  of  the  Stage  of  Growth  209 

Maize  for  silage  {yield  of  dry  matter  per  acre) 

New  York  Maine 

1S89  1893 

Stage  of  growth  lbs.  lbs. 

Tasseled  to  beginning  of  ear 1,620  3,064 

Silked  to  some  roasting  ears    3,080  5,211 

Watery  kernels  to  full  roasting  period  .  4,640  6,060 

Ears  glazing    '.  .  7,200  6,681 

Glazed  to  ripe 7,920  7,040 

Red  clover  (yield  of  dry  matter  per  acre) 

Pennsylvania 
1S82 
Stage  of  gi'owth  lbs. 

In  full  bloom 3,680 

Some  heads  dead 3,428 

Heads  all  dead 3,361 

These  data  are  convincing  testimony  as  to  the 
growth  of  dry  substance  in  certain  forage  crops  up  to 
and  including  the  period  of  ripening.  Clover  is  an 
apparent  exception,  but  is  probably  not  really  so  be- 
cause after  the  heads  begin  to  die  there  is  an  actual 
loss  of  dry  matter  from  the  shedding  of  the  leaves. 

It  does  not  follow  when  a  plant  increases  in  its 
yield  of  dry  matter  that  its  iiutritive  value  has  pro- 
portionately increased.  The  end  to  be  sought  is  the 
largest  possible  quantit}'  of  available  food  compounds, 
and  it  is  entirely  possible  that  changes  in  texture  and 
in  the  composition  of  the  dry  substance  may  partially 
or  fully  offset  the  greater  yield.  With  the  meadow 
grasses  this  undoubtedly  happens.  The  dry  matter  of 
mature  grass  contains  a  larger  proportion  of  fiber  than 
the  immature.  The  progressive  increase  of  fiber  as 
the  plant  approaches  ripeness  is  well  illustrated  by 
analyses   made    at    the    Connecticut    Experiment    Sta- 

N 


210  The  Feeding  of  Animals 

tion    of    a   sample   of   timothy  grass    cut   at   different 
periods  of  growth: 

Composition  of  dry  substance  {per  cent) 


Stage  of  growth  of  timothy 

Ash 

Protein 

Crude 
fiber 

Nitrogen- 
free 
extract 

Fats 

Well  headed  out   

4.7 

9.6 

33. 

50.8 

1.9 

In  full  blossom 

4.3 

7.1 

33.3 

53.3 

2. 

When  out  of  blossom  . 

4.1 

7.1 

33.8 

53.3 

.1.7 

Nearly  ripe 3.6        6.8        35.4      52.2        2. 

These  analyses  show  that  the  changes  are  not  con- 
fined to  an  increase  of  fiber.  The  relative  proportions 
of  ash  and  protein  grow  less  as  the  plant  matures.  An 
examination  of  the  nitrogen -free  extract  would  prob- 
ably show  an  accompanying  decrease  of  the  soluble 
carbohydrates. 

The  combined  effect  of  these  changes  is  to  cause- 
the  plant  to  harden  in  texture  and  become  less  pala- 
table. The  digestibility  is  naturally  affected.  Three 
American  digestion  experiments  with  timothy  hay  cut 
in  bloom  or  before  show  an  average  digestibility  of  the 
organic  matter  of  61.5  per  cent,  the  average  from  four 
experiments  with  timothy  cut  when  past  bloom  being 
55.4  per  cent.  Doubtless  the  increase  in  dry  matter 
when  timothy  stands  beyond  the  period  of  full  bloom 
no  more  than  compensates  for  the  decrease  in  digesti- 
bility. Using  the  average  coefficients  of  digestibility 
and  the  average  yields,  as  given  in  this  connection,  the 
yield  of  digestible  organic  matter  would  be  in  full 
bloom,  2,306  pounds,  and  when  out  of  bloom  or  nearly 
ripe,  2,350  pounds.  If  one  considers  the  decrease  in  pala- 
tableness  the  advantage  is  with  the  earlier  cut  hay. 


Influence  of  the  Stage  of  Growth  211 

These  facts  do  uot  pertain  to  timothy  alone.  Other 
meadow  grasses  are  similar  in  their  characteristics  of 
growth.  The  clovers,  and  especially  alfalfa,  deteriorate 
to  a  marked  degree  from  the  same  cause  when  allowed 
to  ripen  too  fully  before  cutting. 

It  is  probable,  all  factors  considered,  that  if  the 
grasses  and  clovers  which  are  cut  for  hay  could  be 
harvested  when  in  full  bloom  a  desirable  compromise 
would  be  effected  between  quantity  and  quality.  Al- 
falfa should  be  cut  no  later  than  when  the  first  bloom 
makes  its  appearance. 

Conditions  are  quite  different  with  maize.  This 
plant  in  maturing  gains  not  only  in  quantity  but  in 
quality.  In  support  of  this  statement  data  are  cited 
from  an  experiment  conducted  at  the  Maine  Experi- 
ment Station. 

The  following  is  the  composition  of  the  dry  matter 
of  the  corn  when  cut  at  several  periods  of  growth: 

In  100  parts  water- free  substance  of  maize 

Total 
nitrogen- 
Cnide  free 

Stage  of  growth  Ash    Protein    fiber    Sugar    Starch    extract    Fat 

Very  immature,  Aug.  15 9.3  15.  26.5  11.7  46.6  2.6 

A  few  roasting  ears,  Aug.  28  ..  6.5  11.7  23.3  20.4  2.1  55.6  2.9 

All  roasting  stage,  Sept.  4   ....  6.2  11.4  19.7  20.6  4.9  59.7  3. 

Some  ears  glazing,  Sept.  12..,.  5.6            9.6  19.3  21.1  5.3  62.5  3. 

All  ears  glazed,  Sept.  21    5.9            9.2  18.6  16.5  15.4  63.3  3. 

Here  we  see  the  same  decrease  in  the  proportions  of 
ash  and  protein  as  occurs  with  timothy,  but,  unlike 
timothy,  the  maturing  of  the  maize  causes  a  decrease  in 
the  percentage  of  fiber  and  a  material  increase  in  the 
relative  amount  of  the  soluble  carbohydrates,  sugar 
and  starch. 


212  The  Feeding  of  Animals 

These  data  give  us  every  right  to  expect  that  the 
dry  matter  of  the  mature  corn  plant  is  more  digestible 
than  that  of  the  immature  plant,  and  experimental 
tests  show  this  to  be  the  case.  There  follows  a  sum- 
mary of  American  digestive  experiments  bearing  on 
this  point: 

Digested  from  100  parts  organic  matter 

> — Corn  fodder — ■ Corn  silage « 

Max.     Min.       Av.       Max.      Min.       Av. 

Cut  before  glazing,  13  experiments  . .     71.4        53.6        65.7        77.8        56.6        67.4 
Cut  after  glazing,  10  experiments....     74.2        61.2        70.7        80.2        65.2        73.6 

The  advantage  is  seen  to  be  with  the  mature  corn. 
It  is  fair  to  conclude  from  all  these  observations  that 
harvesting  the  corn  plant  when  immature  is  injudicious 
from  every  point  of  view. 

SILAGE 

About  twenty -five  years  ago  a  new  process  for  pre- 
serving crops  in  a  green  condition  was  introduced  into 
the  United  States;  viz.,  ensilage.  This  consists  in 
storing  green  material  in  receptacles  called  silos,  in 
masses  sufficiently  large  to  insure  certain  essential  con- 
ditions. Within  a  brief  period  after  maize  or  other 
green  material  is  packed  in  a  silo,  the  mass  becomes 
perceptibly  warm  and  in  the  course  of  two  or  tliree 
days  it  reaches  its  maximum  temperature,  which  is  much 
above  the  average  heat  outside.  This  rise  in  temper- 
ature is  due  to  chemical  changes  which  involve  the 
consumption  of  more  or  less  oxygen  and  the  produc- 
tion of  compounds  not  previously  existing  in  the  fresh 
material. 


Silage  Formation  213 

Kature  of  the  changes  in  the  silo. — These  changes 
are  very  complex.  Thej'  have  been  regarded  as  due  to 
the  activity  of  a  variety  of  ferments,  principally  those 
which  are  believed  to  cause  the  formation  of  alcohol 
and  acetic,  lactic  and  other  acids.  Whether  the  oxi- 
dations occurriug  in  the  silo  are  wholly  induced  by 
ferment  action  or  in  part  at  least  are  the  result  of 
oxidations  brought  about  in  other  ways  is  a  point  over 
which  there  has  been  some  recent  interesting  discussion. 

Babcock  and  Russell  have  carried  on  at  the  Univer- 
sity of  Wisconsin,  able  and  very  suggestive  inves- 
tigations concerning  the  causes  of  silage  formation. 
They  conclude  that  the  theory  that  silo  changes  under 
normal  conditions  are  due  whollj^  to  bacteria  "does 
not  rest  on  a  sound  experimental  basis." 

Their  data  lead  them  to  regard  respiratory  processes, 
both  direct  bj'  the  plant  cells  and  intramolecular,  as 
the  main  causes  of  the  chemical  transformations  Avhich 
produce  carbon  dioxid  and  the  evolution  of  heat  within 
the  ensiled  mass.  The  direct  respiration  appropriates  the 
oxygen  confined  in  the  air  spaces  of  the  silo,  and  the 
intramolecular  respiration  uses  oxygen  combined  in  the 
tissues.  Both  forms  of  respiration  go  on  only  so  long 
as  the  plant  cells  remain  alive.  Concerning  bacteria 
the  authors  say:  "The  bacteria,  instead  of  function- 
ing as  the  essential  cause  of  the  changes  produced 
in  good  silage,  are  on  the  contrary  only  deleterious. 
It  is  only  where  putrefactive  changes  occur  that  their 
influence  becomes  marked." 

Whatever  are  the  inducing  causes,  the  chemist  finds, 
when  he  keeps  a  careful  record  of  what  takes  place  in 


214  The  Feeding  of  Animals 

the  silo,  that  the  silage  contains  considerabh^  less  dry 
substance  than  the  original  fresh  material.  In  some 
way  loss  has  occurred  through  the  formation  of  volatile 
products.  An  examination  of  the  fresh  corn  and  of  the 
silage  shows,  moreover,  that  the  latter  contains  much 
less  sugar  than  the  former,  sometimes  none  at  all.  In 
the  place  of  the  sugar  we  find  a  variety  of  acids,  chiefly 
acetic  and  lactic.  This  is  a  change  similar  to  the  for- 
mation of  acetic  acid  in  cider  and  lactic  acid  in  milk, 
in  all  cases  sugars  being  the  basal  compounds.  Along 
with  the  development  of  these  acids,  carbon  dioxid  and 
water  are  formed  from  the  carbon  compounds  of  the 
ensiled  material.  In  other  words,  combustion  takes 
place  and  more  or  less  of  dry  matter  is  actuallj^  burned 
up,  thus  generating  heat  and  causing  rise  of  temperature 
of  the  fermenting  mass.  The  amount  of  dry  matter 
thus  lost  is  determined  partly  by  the  kind  of  crops 
and  the  care  with  which  the  silo  is  built  and  filled. 

Another  important  chemical  change  induced  by  fer- 
mentation is  a  splitting  up  of  a  certain  portion  of  the 
proteids  of  the  fermenting  material  into  amides,  com- 
pounds which,  as  we  have  learned,  have  a  more  limited 
nutritive  function  than  the  proteids.  Investigation 
conducted  at  the  Pennsylvania  State  College  showed 
that  in  some  cases  over  half  the  nitrogen  of  silage 
existed  in  the  amide  form,  this  being  between  two  and 
three  times  as  much  as  was  found  in  the  original  fodder. 
Probably  the  same  change  takes  place  in  the  field- 
curing  of  fodder,  but  no  data  are  available  on  this  point. 

All  observers  agree  so  far  that  with  normal  silage 
much   the   larger  part   of   the  material   lost   is  sugar. 


Changes  and  Losses  in   the  Silo  215 

Starch  seems  to  resist  the  usual  silo  oxidations.  In 
certain  experiments  a  considerable  loss  of  nitrogen  is 
reported.  It  is  hard  to  understand,  though,  how  this 
can  occur  to  any  large  extent  unless  the  conditions  in 
the  silo  are  very  bad,  so  that  putrefactive  fermentations 
set  in.  An  extensive  loss  of  nitrogen  compounds  cer- 
tainly would  indicate  very  serious  and  long -continued 
destructive  changes. 

The  nature  of  the  changes  and  losses  in  producing 
silage  have  been  dwelt  upon  partly  because  corn,  the 
principal  silo  crop,  is  one  of  our  most  important  forage 
crops,  perhaps  the  most  so  on  a  dairy  farm,  and  partly 
in  order  to  illustrate  the  necessity  and  value  of  good 
management  in  preserving  this  crop  by  the  silo  method. 
Moreover,  the  loss  that  is  incident  to  the  field -curing 
of  maize  is  practically  the  same  in  kind  and  is  fully  as 
large  as  that  pertaining  to  silage,  so  that  the  facts  pre- 
sented are  pertinent  to  both  methods  as  well  as  to  all 
circumstances  where  similar  oxidations  and  fermenta- 
tions are  likelj"  to  ensue. 

Extent  of  Joss  in  the  s^7o.— The  extent  of  the  loss  of 
dry  substance  is  important.  It  measures  in  a  general 
way  the  difference  between  the  food  value  of  the  silage 
and  of  the  fresh  material.  The  silo  combustion  reduces 
the  energy  or  heat  value  which  the  fermented  fodder 
will  have  whenever  it  is  eaten  by  the  animal.  The 
heat  lost  would  warm  an  animal  during  a  cold  day  were 
the  combustion  to  occur  within  the  animal  instead  of  in 
the  silo.  It  is  desirable,  therefore,  to  know  the  extent 
to  which  dry  substance  is  actually  broken  up  in  the 
preparation  of    silage.      This  loss  has  been  measured 


216  The  Feeding  of  Animals 

by  several  investigators,  and,  as  was  to  be  expected, 
it  has  been  found  to  depend  greatly  upon  the  condi- 
tions involved,  the  figures  reached  varying  from  about  2 
per  cent  to  nearly  40  per  cent  of  the  dry  matter  of  the 
fresh  crop.  In  a  majority  of  cases  the  loss  has  been 
over  15  per  cent  and  less  than  20  per  cent.  Professor 
King,  of  the  Wisconsin  Experiment  Station,  who  has 
given  the  production  of  silage  much  study,  concludes 
upon  the  basis  of  his  observations  that  in  good  prac- 
tice the  necessary  reduction  of  dry  matter  in  making 
corn  silage  need  not  exceed  4  to  8  per  cent,  and  with 
clover  silage  from  10  to  18  per  cent.  The  necessary 
loss  is  explained  as  being  that  which  occurs  in  the 
interior  of  the  mass  where  all  outside  air  is  excluded 
and  other  favorable  conditions  prevail.  Considering 
the  contents  of  the  silo  as  a  whole,  it  will  require  care- 
ful attention  to  all  details  in  order  to  reach  Professor 
King's  estimate  with  the  best  conditions  attainable. 

This  investigator  found  that  64.7  tons  of  silage 
packed  in  a  silo  lined  with  galvanized  iron,  thus  secur- 
ing a  perfect  exclusion  of  air,  lost  an  average  of  6.38 
per  cent  of  dry  matter.  This  silo  was  filled  in  eight 
detached  layers,  and  the  proportion  of  loss  in  these  sev- 
eral divisions,  as  affected  by  location,  is  most  suggestive: 

Surface  layer. . .   8,934  lbs.,  lost  32,53  per  cent  dry  matter 


Seventh  layer  .  .   8,722 

Sixth  layer 14,6Gl 

Fifth  layer 48,801 

Fourth  layer  ...13,347 

Third  layer 7,723 

Second  layer  .  ..12,G89 
Bottom  layer  ...12,619 


23.38 
10.25 
2.10 
7.01 
2.75 
3.53 
9.47 


Extent  of  Silo  Losses  217 

The  mean  loss  of  diy  matter  in  the  lower  six  layers 
was  onh-  3.66  per  cent.  These  figures  show^  that  it  is 
profitable  to  make  the  walls  of  the  silo  air-tight,  even 
at  large  expense. 

The  importance  of  reducing  the  loss  in  the  silo  to 
the  lowest  possible  percentage  is  almost  self-evident. 
As  this  point  is  capable  of  mathematical  demonstration, 
it  will  be  interesting  and  suggestive  to  calculate  what 
might  take  place  in  a  hundred- ton  silo.  In  many  of 
the  trials  which  appear  to  have  been  conducted  under 
not  unusual  conditions,  a  loss  as  high  as  20  per  cent  of 
the  dry  matter  put  in  the  silo  has  been  observed.  In 
a  hundred -ton  silo  filled  with  corn  containing  25  per 
cent  of  dry  matter,  or  50,000  pounds,  this  would  amount 
to  the  destruction  of  10,000  pounds  of  dry  food  sub- 
stance. As  the  loss  falls  chiefly  on  the  sugars  or  other 
soluble  bodies  which  are  wholly  digestible,  the  available 
nutrients  in  the  fresh  material  are  diminished  by  an 
amount  of  digestible  dry  matter,  equivalent  to  what 
w^ould  be  required  by  ten  milch  cows  during  two 
months.  If,  therefore,  by  good  planning  and  extra 
care  this  waste  could  be  reduced  three -fourths  or  even 
one -half,  the  food  resources  for  carrying  a  herd  of 
cows  through  the  winter  would  be  materially  increased, 
from  five  to  seven  and  one -half  tons  of  timothy  hay 
being  the  measure  of  the  saving  in  a  hundred-ton  silo. 

Ensiling  vs.  field-curing.  —  The  question  is  often 
raised  whether  ensilage  or  field  -  curing  is  the  more 
wasteful  method  of  preserving  a  forage  crop.  Con- 
siderable study  has  been  given  this  matter,  and  the 
results  secured  have  been  taken  as  a  justification  of  the 


218  Tlie  Feeding  of  Animals 

statement  that  one  method  is  about  as  economical  as 
the  other,  which  is  correct  if  we  consider  only  the  out- 
come of  certain  comparisons.  A  general  survey  of  the 
data  accumulated  shows  that  on  the  whole  the  waste 
has  been  the  larger  in  field  -  curing.  Observations 
made  in  six  states  reveal  a  loss  by  the  old  method 
as  low  as  18  per  cent  in  only  one  case,  and  from  21 
per  cent  to  34  per  cent  in  all  others.  Possibly  under 
favorable  conditions  of  weather,  field -cured  corn  fodder 
may  lose  as  little  dry  matter  as  silage,  though  this  is 
doubtful,  but  in  bad  weather  the  waste  from  the  ex- 
posed fodder  is  extensive.  The  greatest  advantage  in 
silo  preservation  is  that  conditions  can  usually  be  con- 
trolled with  more  satisfactory  average  results  than  are 
possible  in  field -curing.  Other  advantages  pertain  to 
the  silo  which  are  of  a  business  nature  and  which  need 
not  be  discussed  here,  further  than  to  affirm  that  the 
cost  of  a  unit  of  food  value  is  in  general  diminished 
by  the  use  of  the  silo. 

Crops  for  ensilage. — The  number  of  crops  that  may 
be  successfully  ensiled  is  not  large.  Maize  is  the  most 
valuable  one  for  this  purpose,  and  clover  is  stored  in 
this  manner  with  a  fair  degree  of  success.  So  are 
peas,  especially  when  mixed  with  corn.  The  true 
grasses  and  cereal  grains  outside  of  corn  are  not  de- 
sirable silo  crops,  first  because  the  silage  from  them 
is  generally  poor  in  quality,  and  second  because  usually 
they  may  be  successfully  and  more  cheaply  stored  in 
an  air -dry  condition.  Any  crop  with  a  hollow  stalk, 
giving  an  enclosed  air  space, — oats,  for  instance, — is  not 
adapted  to  silo  conditions,  and  there  is  no  justification 


Construction  of  the  Silo  219 

for  ensiling  any  fodder  which  is  susceptible  of  prompt 
and  thorough  drying  in  the  field,  because  in  such  cases 
there  is  an  unnecessary  waste  of  food  substance  by  fer- 
mentation and  an  unnecessary  handling  of  many  tons 
of  water  contained  in  the  green  material,  with  no  com- 
pensating advantages.  But  any  crop  used  for  the 
production  of  silage  should  be  managed  in  the  most 
efficient  manner.  A  few  general  facts  may  be  discussed 
ill  this  connection. 

Construction  of  silos.  —  Silos  that  are  of  proper 
construction  and  shape  have  air-tight  perpendicular 
walls  and  a  height  considerably  in  excess  of  either  of 
the  horizontal  dimensions.  These  conditions  are  essen- 
tial to  the  completest  possible  exclusion  of  air  and  to 
the  closest  possible  packing  of  the  material,  with  a 
minimum  of  exposed  upper  surface. 

Silos  may  be  either  round,  square  or  rectangular, 
provided  that  in  the  latter  case  one  horizontal  dimen- 
sion is  not  too  greatly  in  excess  of  the  other.  The 
shape  of  a  silo  which  is  most  economical  and  efficient 
i«  not  the  same  for  all  conditions,  although  the  round 
and  square  forms  hold  most  in  proportion  to  the  wall 
area.  Many  farmers  desire  to  have  the  silo  in  the  barn, 
and  generally  there  the  square  or  rectangular  form  is 
inore  economical  of  space  than  a  round  one.  When 
built  outside  the  barn,  the  round  form,  according  to 
the  opinion  of  many,  may  be  used  to  advantage  both 
as  to  expense  and  results.  If  a  square  or  rectangular 
silo  is  built  the  corners  should  be  cut  off  inside  in 
order  to  prevent  an  access  of  air  and  the  decay  which 
occurs  at  those  points  when  this  is  not  done.     Several 


220  The  Feeding  of  Animals 

kinds  of  materials  have  been  used  in  building  silos, 
wood,  brick,  and  stone,  the  former  material  proving  to 
be  the  most  satisfactory.  If  the  walls  are  of  masonry 
the  inner  surface  must  be  cemented  not  onl}'  air-tight 
but  so  smoothly  as  to  allow  easy  and  uniform  settling 
of  the  silage  without  leaving  air  spaces.  If  wood  is 
used,  which  is  certainly  to  be  preferred,  the  inside  con- 
struction must  meet  the  same  requirements.  Lining  a 
wooden  silo  with  iron  has  been  suggested  as  practical 
and  economical.  Economy  demands  that  as  a  pre- 
ventive against  decay  the  inner  woodwork  should  at 
least  be  treated  with  some  preservative,  which  may  also 
serve  the  purpose  of  obviating  excessive  swelling  and 
shrinking  of  the  lining  boards. 

Filling  the  silo. — The  condition  of  the  crop  and  the 
manner  of  filling  a  silo  determine  to  a  great  extent  the 
character  of  the  silage.  Obviously  it  should  be  so 
done  as  to  reduce  the  loss  of  food  compounds  to  the 
lowest  possible  point.  Three  points  are  prominently 
discussed  in  this  connection:  (1)  the  condition  of  the 
crops;  (2)  the  preparation  of  the  material,  and  (3)  the 
rate  of  filling. 

Experience  has  thoroughly  demonstrated  that  the 
maturity  of  a  crop  influences  its  value  for  silage.  This 
is  known  to  be  especially  true  of  the  corn  crop.  An 
immature  corn  fodder,  which  always  carries  a  high 
percentage  of  water  with  less  of  the  matured  products, 
such  as  starch,  is  always  certain  to  change  to  very  acid 
silage.  On  the  contrarj^  m-ature  corn,  when  properly 
handled,  is  converted  into  a  product  with  the  minimum 
aciditj^    and    with    an    appearance    and    aroma    much 


Filling  the  Silo  221 

superior  to  that  from  the  immature  plant.  Neither  are 
satisfactory^  results  secured  from  material  that  is  over- 
dry.  It  may  be  stated  in  general  terms  that  the  best 
results  are  obtained  when  the  proportion  of  dry  matter 
falls  between  25  per  cent  and  30  per  cent.  If  corn  is 
harvested  for  the  silo  after  the  kernels  have  begun  to 
glaze,  while  the  leaves  are  still  green  and  before  they 
show  dryness,  other  conditions  being  favorable,  it  will 
meet  every  requirement  for  good  silage. 

Whether  the  material  with  which  a  silo  is  filled  shall 
be  put  in  whole  or  after  cutting  or  shredding  depends 
to  quite  an  extent  upon  its  degree  of  coarseness.  It  is 
probable  that  clover,  and  even  the  smaller  varieties  of 
maize,  are  often  successfully  preserved  without  cutting, 
but  no  one  professes  that  this  can  be  done  with  the 
coarser  varieties  of  maize.  It  is  generally  admitted 
that,  with  maize,  cutting  or  shredding  it  increases  the 
probability  of  satisfactory  preservation,  because  the 
finer  mechanical  condition  allows  more  uniform  pack- 
ing and  prompter  and  more  uniform  settling.  The 
highest  grade  of  silage  with  the  minimum  loss  is 
undoubtedly  more  surely  made  from  cut  or  shredded 
material. 

In  the  early  daj^s  of  silos  it  was  taught  that  to 
insure  the  least  possible  waste  by  fermentation,  the  silo 
should  be  filled  with  the  maximum  rapidity  and  then 
promptly  weighted.  Following  this  view  was  the  con- 
clusion on  the  part  of  some  that  very  slow  filling  with 
no  packing  other  than  that  given  by  the  weight  of  the 
mass,  was  the  proper  way  to  make  silage  of  the  highest 
quality.      This    method   was    advocated   for   producing 


222  The  Feeding  of  Animals 

sweet  (?)  silage.  It  allowed  violent  fermentation  at 
first  with  resulting  high  temperatures,  by  which  means 
bacteria  were  supposed  to  be  killed  and  subsequent 
fermentations  prevented,  a  conclusion  so  far  not  sus- 
tained by  scientific  observations.  At  the  present  time 
moderately  slow  and  continuous  filling,  rather  than 
very  rapid,  is -advocated  by  leading  authorities.  Two 
advantages  are  claimed  for  this  method,  one  being  that 
more  material  can  be  stored  in  the  silo  and  the  other 
is  that  silage  of  a  higher  quality  is  produced  with  a 
smaller  loss  of  dry  matter.  The  first  point  must  be 
conceded  and  the  second  claim  may  be  true,  although 
in  part  it  lacks  proof.  It  is  hard  to  understand  why  slow 
filling,  especially  if  intermittent,  should  not  increase 
rather  than  decrease  the  losses  of  food  compounds. 
Certainly  the  less  compact  the  mass  the  more  intense 
the  oxidation  and  the  higher  the  temperature,  the  latter 
condition  indicating  with  certainty  the  extent  of  the 
combustion.  This  point  is  illustrated  by  results  reached 
at  the  Pennsylvania  State  College  when  the  chemical 
changes  in  two  large  tubs  of  sorghum  silage  were 
studied,  one  of  which  Avas  compactly  filled  and  Aveighted 
at  once  and  the  other  loosely  filled  and  weighted  after 
five  days.  The  temperature  rose  seventeen  degrees 
higher  in  the  latter  than  in  the  former,  with  a  loss  of 
two  and  one -half  times  as  much  organic  matter  from 
the  loosely  filled  tub.  It  follows  from  the  theory  of' 
Babcock  and  Russell,  previously  noted,  that  the  less 
the  oxygen  available  in  the  air  spaces  and  the  quicker 
the  plant  tissue  dies  the  less  will  be  the  combustion  or 
loss  of   organic  matter.      These  authors  suggest  as  a 


Tlie  Straws  223 

practical  application  of  their  theory  that  the  air  be 
excluded  from  the  silo  as  rapidly  as  possible  and  only 
mature  corn  be  ensiled,  because  such  tissue  will  die 
sooner  than  immature,  having  less  vitality.  Their  data 
seem  to  prove  conclusively,  also,  that  the  evolution  of 
much  heat  when  a  fodder  is  first  ensiled  is  not  essential 
to  the  formation  of  first-class  silage.  The  repeated 
exposure  of  a  loose  upper  stratum,  which  occurs  with 
slow,  intermittent  filling,  must  cause  extensive  loss 
from  portions  of  the  silo.  It  must  be  held,  in  view  of 
the  experimental  data  now  at  hand,  that  the  more 
promptly  the  air  is  excluded  and  expelled  by  the  re- 
duction of  the  contents  of  the  silo  to  a  condition  of 
maximum  compactness,  the  less  will  be  the  fermenta- 
tion losses.  The  term  "sweet  silage"  means  but  little 
as  indicating  completeness  of  preservation,  for  it  may 
even  be  the  result  of  extensive  fermentations,  a  condi- 
tion expensively  secured.  Its  significance  is  entirely 
different  when  the  sweetness  is  due  to  proper  maturity 
of  the  fodder  plant. 

THE    STRAWS 

When  the  grain  plants  which  produce  seeds  val- 
uable for  cattle  and  human  foods  are  threshed, 
or  in  some  way  manipulated  to  remove  the  seeds, 
the  other  parts  of  the  plant  constitute  what  we  call 
straw  in  the  case  of  the  cereal  grains  and  le- 
gumes, and  stover  in  the  case  of  maize.  These  fod- 
ders differ  from  the  same  plants,  when  cut  in  a  less 
mature  condition  for  hay  or  fodder,  in  being  more  tena- 


224  The  Feeding  of  Animals 

cious  and  less  palatable,  with  a  smaller  proportion  of 
the  more  soluble,  and  therefore  more  valuable,  com- 
pounds. The  most  useful  of  these  materials  for  feed- 
ing purposes  are  corn  stover,  oat  straw,  and  the  legume 
straws.  These  are  better  relished  by  farm  animals  than 
wheat  and  barley  straws,  which  are  utilized  mostly 
for  litter. 

ROOTS   AND   TUBERS 

Certain  species  of  plants,  more  especially  beets, 
mangel -wurzels,  turnips,  rutabagas,  carrots  and  pota- 
toes, are  agriculturally  valuable  because  of  the  store 
of  nutrients  which  they  deposit  in  subterranean  branches 
or  in  roots.  The  original  purpose  of  this  deposit  is, 
in  the  case  of  potatoes  and  artichokes,  to  nourish  the 
young  plants  of  the  next  generation,  or,  in  the  case 
of  biennials  like  beets,  to  supply  the  materials  for  the 
seed -stalk  and  seeds  of  the  second  year.  Potatoes  are 
not  grown  primarily  as  food  for  cattle,  but  roots  have 
for  many  years  been  a  standard  crop  for  feeding  pur- 
poses, especially  in  the  production  of  mutton  and  beef. 
This  class  of  crops  has  the  advantage  of  furnishing 
very  palatable,  succulent  food,  which  may  be  kept  in 
perfect  condition  during  the  entire  winter  season,  an 
advantage  which  is  not  wholly  measured  by  the  actual 
quantity  of  nutrients  supplied  by  these  materials. 

The  disadvantages  of  these  crops  are  that  they  are 
somewhat  expensive  to  grow  and  necessitate  the  han- 
dling of  large  weights  of  water.  A  ton  of  turnips  or 
mangels  may  furnish  even  less  than  200  pounds  of  dry 
substance,  to  secure  which  1,800  pounds  of  water  must 


Boots,  Grams  and  Seeds  225 

be  lifted  several  times.  The  percentage  of  dry  matter 
ill  roots  and  tubers  varies  in  American  products,  on 
the  average,  from  9.1  per  cent  in  mangel -wurzels  and 
turnips  to  28.9  per  cent  in  sweet  potatoes.  Potatoes 
are  more  nutritive  pound  for  pound  than  roots.  The 
dry  matter  of  this  class  of  cattle  foods  is  principally 
carbohydrate  in  its  character,  though  the  proportion 
of  protein  is  as  large  and  in  some  cases  larger  than  in 
certain  grain  foods. 

Two  conditions  are  essential  to  the  winter  storage 
of  roots  w^ithout  deterioration;  viz.,  a  low  temperature, 
as  near  freezing  as  possible,  and  abundant  ventilation. 
Large  masses  of  roots  unventilated  are  apt  to  "heat," 
and  sometimes  decay,  with  a  resulting  large  loss  in 
nutritive  value. 

GRAINS    AND     SEEDS 

The  conditions  which  provide  for  the  maintenance 
of  plant  life  also  subserve  the  interests  of  the  animal 
kingdom.  We  have  seen  that  this  is  true  of  the  store 
of  starch  and  other  compounds  in  tubers  and  roots, 
and  it  is  a  fact  of  much  larger  significance  in  the 
production  of  seeds,  especially  those  of  our  cereal 
grains,  including  barley,  maize,  oats,  rice,  rye  and 
wheat.  Other  seeds,  such  as  buckwheat,  cottonseed, 
flaxseed,  beans  and  peas,  also  contribute  an  important 
addition  to  our  animal  feeding  stuffs.  In  all  these 
species  there  is  deposited  in  the  seed-coats  and  either 
around  the  chit  or  embryo  or  in  the  seed-leaves  of  the 
embryo,  a  store  of  protein,  starch  and  oil,  the  purpose 
of   which    is    to    supply   materials    for   growth    during 


226  The  Feeding  of  Animals 

germination.  This  deposit  of  plant  compounds  repre- 
sents the  highest  type  of  vegetable  food,  whether  we 
consider  concentration,  palatableness  or  nutritive  effi- 
ciency. Besides,  it  is  in  such  form  that  with  ordinary 
precautions  it  is  capable  of  indefinite  preservation, 
without  loss. 

It  often  occurs  that  when  newly -harvested  grain 
is  stored  in  bulk  it  heats  and  grows  "musty."  This 
condition  is  due  to  fermentations  that  are  made  pos- 
sible hy  the  high  water  content  of  the  fresh  grain  and 
which  involve  a  loss  of  dry  substance.  It  is  very  de- 
sirable that  grain  shall  be  thoroughly  dried  before 
threshing,  and  it  is  generally  necessary  to  secure 
additional  drying  after  threshing  before  storing  it  in 
large  bins. 

The  agricultural  value  of  the  cereal  grains  is  much 
enhanced  by  their  adaptability  to  a  great  range  of 
soil  and  climatic  conditions.  They  are  the  American 
farmer's  great  reliance  for  the  production  of  the  high- 
est class  of  cattle  foods.  Maize,  especially,  is  grown 
from  Maine  to  Florida  and  from  the  Atlantic  to  the 
Pacific.  These  crops  are  useful,  not  only  for  their 
seeds  but  as  fodder  plants.  For  soiling  purposes,  as 
well  as  a  source  of  dried  forage,  they  are  indispen- 
sable. 


CHAPTER   XVI 

CATTLE  FOODS— COMMERCIAL  FEEDING  STUFFS 

The  cereal  graius  and  other  seeds  are  the  source  of 
a  great  variet}-  of  by-product  feeding  stuffs  which  have 
a  large  and  widespread  use,  especially  in  the  dairy 
sections  of  the  United  States,  In  the  preparation  of 
a  great  variety  of  human  foods  and  of  other  materials 
important  in  industrial  life,  certain  by-products  are 
obtained  which  represent  particular  parts  or  compounds 
of  the  grain  or  seed.  Whenever  the  methods  of  manu- 
facture are  such  as  not  to  injure  the  palatableness  or 
healthfulness  of  these  waste  products,  they  may  be 
utilized  as  cattle  foods.  As  a  matter  of  fact,  a  large 
proportion  of  our  commercial  feeding  stuffs  is  of  this 
general  kind  and  because  these  materials  differ  greatly 
in  composition  and  nutritive  value,  the  purchaser  should 
clearly  understand  their  source  and  character.  Changes 
in  methods  and  new  manufacturing  enterprises  are 
constantly  modifying  the  composition  of  old  products 
and  introducing  new  ones,  consequently  the  facts  as 
they  exist  at  one  time  may  not  be  applicable  for  a 
long  period.  There  is  need  therefore  of  constantly 
keeping  informed  in  regard  to  the  various  cattle  foods 
found  in  the  markets,  if  they  are  to  be  economically 
purchased  and  wisely  used. 

(227) 


228  The  Feeding  of  Animals 

CLASSES    OF    COMMERCIAL    BY-PRODUCT    FEEDING    STUFFS 

For  the  purposes  of  description,  the  various  by- 
product feeding  stuffs  may  be  classified  according  to 
their  origin.     Their  sources  are  mainly  as  follows: 

1.  The  milling  of  wheat  and  other  grains. 

2.  The   manufacture   of   oatmeal  and    a    variety  of 

breakfast  foods. 

3.  The    numufacture   of   beer    and    other    alcoholic 

drinks. 

4.  The   manufacture  of   starch   and   sugars,  chiefly 

from   corn. 

5.  The   extraction    of    oils,    chiefly  linseed   oil   and 

cottonseed  oil. 

Wheat  offals. — No  commercial  feeding  stuffs  are 
regarded  with  greater  favor,  or  are  more  widely  and 
largely  purchased  by  American  feeders  than  the  by- 
products from  milling  wheat.  Wheat -bran  and  mid- 
dlings are  cattle  foods  of  standard  excellence,  wiiether 
we  consider  composition,  palatableness  or  their  relation 
to  the  quality  of  dairy  products.  Tht^se  feeding  stuffs 
consist  of  particular  parts  of  the  wheat  kernel,  a  knowl- 
edge of  the  structure  of  which  aids  greatly  in  under- 
standing what  they  are  and  why  they  possess  certain 
chemical  and  physical  properties. 

To  ordinary  observation  the  wheat  grain  appears  to 
be  merely  a  seed,  but  it  is  really  a  seed  contained  in  a 
tightly -fitting  seed -pod.  This  pod,  which  is  woody  and 
tough,  constitutes  the  outer  coating  of  the  kernel.  On 
the  seed  itself  are  two  more  hard  and  resisting  coat- 
ings, one  of  which  is  double,  that  serve  to  protect  the 


Stmctnre  of  the   Wheat  Kernel 


229 


softer  parts.  We  find,  then,  that  in  every  wheat  ker- 
nel there  are  three  coats  entirely  unlike  the  rest  of  the 
grain,  because  they  consist  of  hard,  thick -walled  cells 
containing  but  little  starch,  if  any,  with  a  much  larger 
proportion  of  cellulose  or  fiber  than  is  found  in  the 
inner  portion  of  the  kernel.     Figs.  4  and  5. 

Just  inside   the  innermost  of  the  three  outer  coats 
is  a  layer  of  material  very  rich  in  protein  compounds, 


Fig.  4.     Section  of  entire  wheat  kernel  (enlarged  16  diameters). 
1,  Seed  pod  and  seed  coatings.    4,  Gluten  laj'er.    5,  Mass  of  starch  cells. 

which  may  properly  be  called  the  gluten  laj-er.  The 
great  bulk  of  the  wheat  kernel  is  made  up  of  cells 
closely  filled  with  starch  grains.  This  is  the  soft  white 
portion  of  the  seed  and  is  that  which  furnishes  the 
flour.  All  of  these  parts  serve  to  protect,  and,  in  ger- 
mination, to  nourish  the  essential  portion  of  the  seed, 
the  germ  or  embryo  which  lies  "at  the  lower  end  of  the 


230 


The  Feeding  of  Animals 


rounded  back  of  the  kernel."  Bessey,  in  an  admirable 
description  of  the  wheat  kernel,  tells  us  that  the  per- 
centage proportions  of  its  various  parts  are  as  follows: 


Per  cent 

Coatings 5 

Gluten  layer 3-4 


Per  cent 

Starch  cells 84-86 

Germ    6 


We  are  now  prepared  to  understand  the  significance 
of   the  statement  that   in    milling  wheat   the   flour   of 


Fig.  5.     Pai'tial  section  of  wheat  kernel  (enlarged  155  diameters). 

1.  Seed  pod.  3.  Inner  seed  coat. 

2.  Outer  seed  coat.  4.  Gluten  cells.  5.  Starch  cells. 

various  grades  comes  from  the  starch  cells,  the  other 
portions  passing  into  the  bran,  shorts  and  middlings, 
which  collectivelj^  are  termed  the  offal.  If  onlj^  the 
coatings,  gluten  layer  and  germ  went  to  make  up  the 
offal  it  would  include  only  about  14  or  15  per  cent 
of  the  kernel,  the  flours  taking  the  remainder,  but,  as 
a  matter  of  fact,  no  milling  methods  so  far  used  com- 
pletely separate  the  starch  cells  from  the  enclosing  tissue, 
so  that  the  offal  is  perhaps  never  less  than  25  per  cent 


Offals  from   Milling   Wheat  231 

of  the  whole  grain.  In  milling  tests  conducted  bj^  the 
Minnesota  Experiment  Station,  the  offal  from  several 
lots  of  wheat,  good  and  bad,  varied  from  25  per  cent 
to  40  per  cent.  If  four  bushels  of  wheat  are  consumed 
per  capita  by  the  population  of  the  United  States, 
which  is  below  the  estimate,  and  if  only  one- quarter  of 
this  is  converted  into  offals,  the  amount  of  bran  and 
middlings  annually  consumed  by  our  domestic  animals 
is  2,250,000  tons,  barring  the  quantity  which  may  be 
exported. 

It  is  a  fact  worthy  of  special  comment  that  because 
of  a  somewhat  irrational  standard  of  excellence  for 
bread,  certain  parts  of  the  wheat  kernel  best  adapted 
to  the  nourishment  of  young  and  growing  animals  are 
separated  with  great  care  to  be  used  by  the  brute  life 
of  the  farm  rather  than  by  the  farmer  and  his  family. 
A  comparison  of  the  composition  of  the  whole  wheat 
kernel,  white  flour  and  the  various  parts  of  the  offal 
emphasizes  this  point.  The  figures  given  are  taken  from 
the  results  of  an  investigation  by  Snyder,  of  Minnesota, 
in  which  he  compared  the  composition  of  different 
grades  of  wheat  with  that  of  the  flour  and  products 
obtained  from  them: 

Composition  of  wlieat  and  its  milling  products  (per  cent) 


Water 

Ash 

' — Protein — • 
Total  Gluten 

Fiber 

Nitrogen- 
free 
extract 

Starch 

and  dex 

trine 

Fat 

Wheat  kernel. . 

10.2 

1.8 

13.7     13.5 

3.2 

69. 

64.9 

2.0 

Wheat  flour. . . 

10.6 

.4 

11.2     11. 

77.3 

70.4 

.5 

Wheat  germ  . . 

10.4 

2.7 

15.7     15.3 

67.7 

3.5 

Wheat  shorts  . 

10.1 

3.1 

13.1     12.9 

5.4 

65.3 

2.9 

Wheat  bran. . . 

10.4 

5.9 

15.4     14.8 

10.2 

52.9 

5. 

232  The  Feeding  of  Animals 

The  greater  richness  of  the  coatings  of  the  kernel 
in  mineral  matter,  protein,  fiber,  and  oil  is  made  plain 
by  this  comparison.  There  is  fonr  times  as  large  a 
percentage  of  mineral  matter  and  of  oil  in  the  whole 
wheat  as  in  the  flonr,  nearly  one -third  more  protein 
and  considerably  less  starch.  On  the  other  hand,  the 
bran  is  not  less  than  ten  times  richer  in  mineral  com- 
pounds and  oil  than  the  flour,  one -third  richer  in  pro- 
tein, with  correspondingly  less  starch.  "Graham"  flour, 
which  contains  more  or  less  of  those  parts  which  pass 
into  the  offal  in  milling  white  flour,  does  not  differ  so 
much  from  the  whole  kernel.  Middlings  differ  from 
bran  in  containing  less  of  the  hard,  tough  coatings  and 
more  of  the  finer  parts  of  the  kernels,  and  this  feed- 
ing stuff  varies  from  the  coarser  kinds  to  the  fancy 
middlings,  according  to  the  proportion  of  starchy  ma- 
terial present.  Red  Dog  flour  is  counted  among  the 
offals  from  milling  wheat,  and  it  represents  the  dividing 
line  between  the  middlings  and  the  high-grade  flour. 

There  is  a  belief  more  or  less  prevalent  that  bran 
from  the  old  milling  processes  which  contained  more 
of  the  starchy  part  of  the  kernel  than  is  now  the 
case,  was  more  valuable  than  roller  process  bran  is. 
It  is  probable  that  a  greater  proportion  of  starch  in- 
creases the  digestibility  of  bran,  and  in  this  sense  the 
old  process  bran  was  superior  to  the  roller  process 
product;  but,  on  the  other  hand,  the  latter  is  more 
nitrogenous  than  the  former  and  is  therefore  more  effi- 
cient as  a  protein  supplement  to  home -raised  foods. 

Residues  from  hreahfast  foods. — In  the  manufacture 
of   breakfast  foods,   the  use    of  which   has   become  so 


Btj -products  from   Oats 


233 


prevalent,  certain  by-products  are  obtained  which  are 
now  found  in  the  market  as  cattle  foods.  The  prepa- 
ration of  oatmeal  and  similar  materials  involves  the 
selection  of  the  finest  oat -grains,  i.  e.,  those  having 
the  largest  kernels,  from  which  the  hulls  are  removed. 
These  hulls  and  the  smaller  oat -grains,  and  perhaps 
bran,  constitute  bj'- products  which,  after  being  finely 
ground,  are  sold  as  oat -feed  and  in  various  mixtures. 


Fig. 
0.  Hull. 


.     Section  of  entire  oat  grain  (enlarged  16  diameters). 

1.  Seed  coat.        4.  Gluten  layer.        5.  Mass  of  starch  cells. 


As  the  sale  of  oat  hulls  as  such,  or  in  a  fraudulent 
way  when  mixed  with  other  substances,  is  likely  to 
occasion  a  financial  loss  to  feeders,  it  is  desirable  to 
clearly  understand  the  situation.  We  shall  accomplish 
this  by  a  study  of  the  relation  of  the  oat  hulls  to  the 
kernel  in  quantity  and  composition.     Figs.  6  and  7. 

It  is  common  knowledge  that  the  oat -grain  con- 
sists of  a  hull  and  kernel,  which  are  easily  separated. 
The  former  is  fibrous  and  tough,  and  the  latter  soft 
with  very  little  fiber.  The  hull  forms  a  considerable 
portion  of  the  grain.      In  1894,  the  Ohio   Experiment 


234  The  Feeding  of  Animals 

Station  made  a  study  of  numerous  varieties  of  oats. 
It  was  found  that  with  sixty -nine  varieties  the  hulls 
constituted  from  24.6  per  cent  to  35.2  per  cent  of  the 
whole  grain,  the  average  being  30  per  cent.  It  did 
not  appear,  contrary  to  the  general  opinion,  that  the 
proportion  of  hull  was  larger  with  light  oats  than  with 
heavy,  although  observations  elsewhere  have  sustained 
the  popular  view.  At  the  Mustiala  Agricultural  Col- 
lege twenty -eight  samples  of  Finnish  oats  and  twenty 
samples  from  five  other  counties  gave  from  28  to  32  per 
cent  of  hulls.  Wiley  states  that  the  average  propor- 
tion of  hull  to  kernel  is  as  three  to  seven,  which  varies 
with  the  locality  in  which  the  oats  are  grown.  The 
figures  in  the  next  table  show  the  composition  of 
the  dry  matter  of  whole  oats,  oat  hulls  and  the  hulled 
kernel  : 

Nitrogen- 
free 

Ash     Protein     Fiber     extract  Fat 

%  %  %  %  % 

Whole  oats,  30  samples 3.4      13.2       10.8      67.  5.6 

Hulls,  New  Jersey 7.2         3.5       32.         56.3  1. 

Hulls,  Vermont 6.9         4.4       29.5       57.2  2. 

Hulls,  Wisconsin 7.8         2.3       50.1       39.  .8 

Hulled  kernels,  179  analyses  .     2.3       15.4         1.5       72.1  8.7 

The  inferiority  of  the  hulls  as  compared  with  the 
whole  grain  or  with  the  hulled  kernels  is  very  appa- 
rent, because  of  their  smaller  proportion  of  protein 
and  oil  and  their  much  larger  percentage  of  fiber.  If 
hulls  are  purchased  at  all  the  price  should  be  on  a  par 
with  that  at  which  the  coarsest  and  cheapest  grades 
of  fodders  are  sold,  and  the  surprisingly  prevalent  dis- 
honest adulteration  of  ground  whole  grains  with   oat 


Residues  from  Barley  and   Corn 


235 


hulls  should  in  some  way  be  prevented  by  official  in- 
spection. Farmers  will  do  well  to  carefully  inquire 
into  the  character  of  the  so-called  oat  feeds  and  mixed 
feeds  offered  to  them.  These  articles  are  often  oat 
hulls,  poor  oats  and  other  refuse  mixed  with  corn  or 
with    by  -  products   of   an-      -    ^  ^ 


8  0 


i  '*(  •  •      » 


.0. 


'  >) 


^^-^  'j^ 


other  class  and  are  dis- 
tinctly inferior  to  the 
whole  grains.  Such  low 
grade  mixtures  are  not 
wisely  purchased  at  prices 
nearly  equal  to  those  rul- 
ing for  whole  cereal  grains 
of  any  kind. 

Other  grains  besides 
oats  are  used  as  the  source 
o  f  specially  prepared 
human  food.  Barley  feed, 
a  by  -  product  from  the 
manufacture  of  pearled 
barley,  like  oat  feed  con- 
sists of  the  hulls  and  por- 
tions of  the  grain  and 
contains  more  fiber  and 
less  starch  than  the  origi- 
nal grain,  its  value  being  proportionately  less.  Hominy 
is  made  from  corn  and  consists  of  the  hard  portions  of 
the  kernel,  leaving  as  a  residue  the  hull,  germ,  and  part 
of  the  starch  cells,  which  collectively  are  sold  as  hominy 
feed  or  chop.  This  differs  from  the  whole  kernel  but 
little  in  composition  and  is  practically  as  digestible. 


^A^ 


Fig 


Partial  section  of  oat  grain 
(enlarged  170  diameters). 

0.  Hull.  4.  Gluten  cells. 

1.  Seed  coat.       5.  Starch  cells. 


236  The  Feeding  of  Animals 

Brewers^  ly -products. — Sugar  in  some  form  is  at 
present  essential  to  the  production  of  alcoholic  bev- 
erages, a  cheap  supply  of  which  is  obtained  by  con- 
verting the  starch  of  certain  cereal  grains  into  maltose, 
which  afterward  passes  into  fermentable  sugars.  This 
result  is  accomplished  by  placing  barley  and  other 
grains  under  such  conditions  of  moisture  and  tempera- 
ture that  they  germinate.  We  have  alreadj^  seen  that 
during  germination  the  starch  of  a  seed  is  converted 
into  maltose  through  the  action  of  a  diastatic  ferment, 
and  the  maltster  arrests  this  germination  at  a  point 
which  gives  the  maximum  quantity  of  sugar.  The 
malted  grains  are  subsequently^  dried  and  the  sprouts 
after  removal  appear  in  our  markets  in  an  air -dry  con- 
dition, constituting  one  of  our  valuable  nitrogenous 
feeding  stuffs.  The  malted  grains  are  then  crushed, 
the  sugar  is  extracted  from  them,  and  the  residue  is 
known  in  commerce  as  brewer's  grains,  a  b}'- product 
feeding  stuff  fairly  rich  in  protein.  The  high  propor- 
tion of  protein  is  due  to  the  fact  that  the  starch  has 
been  partially  used  up,  leaving  the  other  constituents 
behind  in  a  more  concentrated  form.  These  grains  are 
mostly  dried  and  may  then  be  shipped  to  distant  mar- 
kets in  a  perfectly  sound  and  healthful  condition. 

Eesidues  from  starch  and  glucose  manufacture.  — 
Within  a  comparatively  recent  time  the  gluten  meals 
and  feeds  have  assumed  an  important  place  among 
our  commercial  feeding  stuffs.  These  materials  and 
others  bearing  related  names  vary  within  wide  limits 
in  texture  and  composition,  and  concerning  their  quali- 
ties and  value    there    has    existed   among  the   farmers 


structures  of  the  Maize  Kernel 


237 


much  confusion  of  thought.  Even  the  best  informed 
have  not  always  been  promptly  cognizant  of  new 
products  of  this  chxss  or  of  changes  in  the  compo- 
sition of  okler  ones,  so  rapidly  have  new  methods  of 
manufacture  developed. 

The  gluten  meals,  gluten  feeds,  corn  bran,  and  the 
like  are  residues  obtained  in  the  manufacture  of  starch 
and  glucose  from  the  maize  kernel.    This  kernel,  like 


Fig.  8.     Section  of  entire  maize  kernel  (enlarged  10  diameters). 

1.  Outer  layer  of  husk  or  skin.    2.  Inner  layer  of  skin.    4.  Gluten  layer. 

5.  Mass  of  starch  cells. 

that  of  wheat,  is  not  homogeneous  in  structure  and 
composition,  a  condition  which  makes  it  possible, 
through  mechanical  or  chemical  operations,  to  secure  a 
variety  of  by-products  greatly  unlike  in  texture  and  in 
their  proportions  of  nutrients. 

All  this  is  made  plain  through  a  consideration  of 
the  structure  of  the  maize  kernel.  This  seed  is  in  some 
respects  similar  to  that  of  wheat.  We  have  first  an 
outside  husk  or  skin  made  up  of  two  distinct  layers, 
one  less  than  we  find  in  wheat.     This  skin  is  rich   in 


238  The  Feeding  of  Animals 

fiber,  scarcely  any  being  found  in  the  other  portions 
of  the  kernel.  Next  on  the  inside  is  a  layer  of  cells 
rich  in  gluten.  The  body  of  the  kernel  surrounding 
the  germ  or  embryo  consists  of  closely  compacted 
starch  cells,  though  some  of  this  interior  tissue  on  the 
sides  of  the  kernel  next  to  the  walls  is  flinty.  We 
may  properly  speak  of  the  maize  kernel,  then,  as 
consisting  of  four  parts, — the  husk,  the  gluten  layer, 
the  germ,  and  the  starchy  and  hard  part.  Figs.  8 
and  9.  At  the  New  Jersey  Experiment  Station  100 
grains  of  the  maize  kernels  were  separated  as  nearly 
as  possible  into  the  skin,  germ,  and  main  or  starchy 
and  hard  portions.  These  parts  were  analyzed,  and 
below  are  given  the  results: 

Composition   of  dry   substance   of  maize   kernel    (per   cent) 

Nitrogen- 
free  Proportion 
Ash     Protein    Fiber   extract       Fat      of  parts 

Original  kernel 1.7  12.6        2.  79.4  4-3  100. 

Skin 1.3  6.6  16.4  74.1  1.6  5.5 

Germ 11.1  21.7        2.9  34.7  29.6  10.2 

Starchy  and  hard  part .     .7  12.2           .6  85.  1.5  84.3 

These  figures  are  essentially  similar  to  those  obtained 
by  other  investigators,  including  Salisbury,  Atwater, 
and  Balland. 

The  separation  of  starch  cells  from  other  parts  of 
the  kernel  is  now  accomplished  mechanically.  Either 
before  or  after  soaking  in  warm  water,  the  maize  ker- 
nels are  crushed  into  a  coarse  powder.  The  various 
parts  separate  in  water  by  gravity,  the  hulls  floating 
on  the  surface  and  the  germs  sinking  to  the  bottom. 
The  starch  and  harder  portions  of  the  kernel  remain 


By-products  from  Maize  Kernel 


239 


in  suspension  in  the  Avater,  which  is  conducted  slowly 
through  lon^  troughs,  where  the  starch  settles  to  the 
bottom  and  the  more  glutinous  portions  float  off  and 
are  recovered. 

It  is  now  easy  to  see  how  these  various  by- 
products may  differ  widely.  When  made  up  largely  of 
the  hulls  or  bran  they  are  characterized  by  a  relatively 


/  - 


\  ,' 


£'--^irr 


2S%^ 


Fig.  9.    Partial  section  of  maize  kernel  (enlarged  170  diameters). 
1.  Outer  layer  of  skin.    2.  Inner  layer  of  skin.    4.  Gluten  cell.    5.  Starch  cells. 

high  proportion  of  fiber  with  comparatively  low  per- 
centages of  protein  and  fat.  The  presence  of  the 
germs  increases  the  relative  amount  of  protein  some- 
what and  of  the  fat  very  greatly.  The  fine  glutinous 
pan,  that  is  finally  separated  from  the  starch,  when 
unmixed  with  other  materials  is  distinguished  by  its 
high  content  of  protein. 

As  found  in  the  market,  the  principal  brands 
are  "sugar  corn"  or  "starch"  feed,  made  up  mostly  of 
hulls  and  germs;  gluten  meal,  that  comes  from  the  flinty 
portion  of  the  kernel,  and  gluten  feed,  which  is  now  a 


240  The  Feeding  of  Animals 

mixture  of  hulls  and  the  gluten  part.  When  unmixed 
with  other  parts  of  the  kernel,  the  hulls  are  also  known 
as  corn  bran  and  the  germ  portion  from  w^hich  the 
oil  has  been  pressed  is  called,  when  ground,  germ  oil 
meal.  The  corn  bran  contains  the  least  protein  and  the 
gluten  meal  the  most,  while  the  gluten  feed  and  germ 
oil  meal  occupy  a  position  between  these.  It  should 
be  remarked  that  the  commercial  names  for  gluten  prod- 
ucts are  not  always  a  safe  guide  in  their  purchase. 

Residues  from  the  manufacture  of  beet  sngar. — An 
industrj^  apparently  now  on  the  increase  in  the  United 
States,  the  manufacture  of  beet  sugar,  is  offering  to 
farmers  two  waste  products,  sugar  beet  pulp  and  sugar 
beet  molasses.  The  former  is  the  extracted  beet  tissue 
from  which  all  the  sugars  and  more  or  less  of  other 
soluble  compounds  have  been  removed.  This  pulp  as 
it  leaves  the  factory  has  been  found  to  contain  an 
average  of  scarcely  10  per  cent  of  solids.  One  ton  of 
pulp  supplies,  then,  not  over  two  hundred  pounds  of 
total  dry  substance,  or  perhaps  one  hundred  and  sixty 
pounds  of  digestible  dry  substance.  This  means  that 
it  would  require  six  tons  of  pulp  to  supply  as  much  of 
digestible  nutrients  as  one  ton  of  good  hay.  The  solids 
of  the  pulp  must  be  regarded  as  inferior  to  those  of  the 
beets  before  extraction,  because  consisting  more  largely 
of  fiber  and  gums  whose  productive  value  is  below  that 
of  sugar.  Experiments  at  Cornell  University  indicated- 
that  the  pulp  is  worth  about  one- half  as  much  as  corn 
silage,  which  would  be  approximately  the  proportion  of 
digestible  matter  in  the  two  materials. 

Sugar   beet   pulp    is,   however,   a   useful,   succulent 


Residues  from  the   Oil  Seeds  241 

food,  aud  may  be  fed  to  advantage  in  quantities  from 
seventy-five  to  one  hundred  pounds  daily  to  full -grown 
animals,  provided  it  can  be  purchased  at  a  price  pro- 
portional to  its  value. 

The  pulp  is  not  adapted  to  transportation  for  long 
distances  because  of  the  heavy  expense  of  freight  and 
handling,  but  is  most  available  for  consumption  near 
the  factories.     It  may  be  preserved  in  pits  or  silos. 

The  molasses  is  generally  four-fifths  or  more  dry 
substance  and  contains  from  40  to  50  per  cent  of  sugar, 
which  is  all  digestible  and  which  gives  to  this  product 
its  only  value  for  feeding  purposes. 

This  material  has  been  fed  successfully  to  bovines 
and  swine.  When  given  as  an  addition  to  coarse  foods 
and  home -raised  grains  it  obviously  should  be  combined 
with  some  nitrogenous  feeding  stuff  like  gluten  meal 
or  the  oil  meals. 

The  oil  meals  in  general. — Materials  of  this  class 
may  properly  be  regarded  as  among  the  standard  feed- 
ing stuffs.  Because  of  their  uniformity  in  quality  aud 
composition,  their  general  usefulness  in  compounding 
rations  and  their  value  in  maintaining  soil  fertility, 
their  use  has  had  the  sanction  of  scientific  men  and  of 
successful  practice.  The  oil  meals  are  so  called  be- 
cause they  are  the  residues  left  after  the  extraction 
of  the  oil  from  certain  seeds  and  nuts,  among  which 
are  cottonseed,  flaxseed,  hemp  and  poppy  seed,  rape 
seed,  sesame  seed,  sunflower  seed,  cocoanuts,  palm 
nuts,  peanuts,  and  walnuts.  Of  the  residues  from 
these  sources,  those  from  cottonseed  and  flaxseed 
are  most  common   in  the   United   States:    in  fact,   no 


242  The  Feeding  of  Animals 

other  oil  meals  have  become  important  in  our  cattle 
feeding.  A  description  therefore  of  the  production  of 
cottonseed  meal  and  linseed  meal  will  not  only  cover 
the  points  of  practical  interest  to  American  feeders, 
but  will  serve  to  illustrate  the  main  facts  that  pertain 
to  the  manipulation  of  these  oil  seeds. 

,  It  may  be  stated  in  a  general  way  that  two 
methods  are  used  for  removing  vegetable  oils  from 
seeds,  expressing  by  pressure  and  extraction  with  a 
solvent,  both  of  which  are  now  in  use.  In  using  the 
first  method,  it  was  formerly  the  custom  to  express  the 
oil  from  the  cold  crushed  seed,  but  now  the  seed  is  more 
generally  submitted  to  heat,  either  by  boiling  or  steaming, 
afterwards  applying  the  pressure  to  the  warm  material. 
More  oil  is  obtained  by  the  latter  process.  The  second 
or  extraction  method  involves  the  use  of  a  solvent,  gen- 
erally a  light  naphtha,  which  leaves  less  oil  behind 
than  either  cold  or  warm  pressure.  Before  extraction 
the  crushed  seed  is  heated  just  as  when  pressure  is  used. 
Cottonseed  meal. — The  cottonseed  as  gathered  from 
the  plant  consists  on  the  exterior  of  a  mass  of  long 
white  fibers  that  are  attached  to  the  outer  coat  or  hull, 
inside  of  all  of  which  is  the  kernel  or  meat.  The  seed 
is  first  delinted  by  running  it  through  a  gin,  which 
removes  the  lint  or  cotton  of  commerce.  After  this 
operation  there  is  still  attached  to  the  seed  a  soft  down, 
which  is  subsequently  removed  and  which  constitutes 
what  is  known  as  "linters,"  a  short  lint  that  is  used 
in  making  cotton  batting.  The  remaining  portion  is 
that  from  which  cottonseed  oil  and  certain  by-product 
feeding  stutfs  are  produced. 


Cottonseed  By-products  243 

The  first  process  in  the  mauufacture  of  the  oil  is 
to  remove  the  hull  from  the  inside  meat.  This  is  done 
by  a  sheller,  which  breaks  the  seed -coat  and  forces  it 
from  the  kernel.  These  seed -coats,  which  constitute 
from  45  to  50  per  cent  of  the  delinted  seeds,  are  known 
in  commerce  as  cottonseed  hulls,  and  are  used  to  some 
extent  as  a  feeding  stuff.  They  are  characterized  by  a 
very  low  proportion  of  protein  and  a  very  high  con- 
tent of  fiber.  Twenty -two  analyses  show  a  range  of 
protein  from  1.6  per  cent  to  4.4  per  cent,  and  of  fiber 
from  35.7  to  66.9  per  cent.  Such  material  as  this  be- 
longs with  the  very  lowest  grade  of  coarse  fodder,  as 
both  composition  and  experience  demonstrate.  The 
hulless  kernels  make  up  from  50  to  55  per  cent  of 
the  delinted  seed,  and  from  those  the  oil  is  obtained. 
These  meats  are  first  cooked  twenty  or  thirty  minutes 
in  large,  steam -jacketed  kettles  in  order  to  drive  off  the 
water  and  render  the  oil  more  fluid,  and  then  after 
being  formed  into  cakes  in  wire  cloths,  they  are  sub- 
mitted to  a  pressure  of  3,000  to  4,000  pounds  to  the 
square  inch.  This  removes  at  least  four -fifths  of  the 
oil  and  leaves  the  cakes  very  solid,  which  after  dry- 
ing are  cracked  and  then  ground  into  a  fine  meal, 
known  in  commerce  as  cottonseed  meal.  Formerly  a 
ton  of  ginned  seed  yielded  the  following  quantities  of 
the  different  parts: 

Linters 20  pounds 

Hulls 891       " 

Cake  or  meal , 800       *' 

Crude  oil 289       " 

Since  the  above   estimate  was   prepared  the   manufac- 


244  The  Feeding  of  Animals 

turing  process  has  been  so  improved  that  froni  forty 
to  forty -five  gallons  of  oil  are  now  obtained  from  a 
ton  of  seed,  giving  a  correspondingly  smaller  amonnt 
of  cake.  Chemists  are  well  aware  that  cottonseed 
meal  at  the  present  time  is  less  rich  in  oil  than  was 
the  case  a  few  years  ago. 

When  we  learn  that  no  less  than  1,500,000  tons  of 
cottonseed  are  worked  annually  at  oil  mills,  which  in- 
volves the  production  of  about  600,000  tons  of  meal, 
we  realize  the  importance  of  this  by-product  feeding 
stuff,  and  the  future  possibilities  are  seen  in  the  fact 
that  only  about  one -third  of  the  seed  now  grown  finds 
its  way  to  the  oil  mills.  The  composition  of  the  cotton 
oil  by-products  may  properly  be  stated  in  this  con- 
nection : 

Water  Ash  Protein     Fiber 

%  %  % 

Cottonseed 9.9  4.7       19.4 

Cottonseed  hulls...  11. 4  2.7         4.2 

Cottonseed  kernels.   G.9  G.9       30.3 

Cottonseed  cake...   8.6  7.        44.1 

These  figures  represent  the  composition  of  the  several 
materials  when  the  separations  are  fairly  complete. 
Cottonseed  products  are  sometimes  sold,  however,  in 
a  more  or  less  mixed  condition.  There  has  been  found 
in  the  market  undecorticated  cottonseed  meal,  or  the 
meal  with  all  the  hulls  ground  in  without  removal 
from  the  seed.  Practically  all  the  meal  found  in  the 
markets  now  is  the  decorticated,  or  that  free  from 
hull.  This  should  be  light  yellow  in  color  and  have  a 
slightly  nutty  flavor.     It  should  show  few  or  no  black 


Fiber 

Nitrogen- 
free 
extract 

Fat 

% 

% 

% 

22. C 

24. 

19.4 

45.3 

34.2 

2.2 

4.8 

21.4 

29.6 

4.9 

21.2 

14.2 

Linseed  Meal  245 

specks,  because  the  presence  of  these  indicate  either 
accidental  or  intentional  adulteration  with  hulls.  Cot- 
tonseed feed,  which  appears  to  have  found  only  a 
limited  use,  is  a  finely -ground  mixture  of  cottonseed 
hulls  and  cottonseed  meal,  and  its  value  is  usually 
much  less  than  that  of  the  pure  meal. 

Linseed  meal  {oil  meal). — The  original  source  of 
this  feeding  stuff  is  the  flax  plant.  This  plant  serves 
a  very  useful  purpose  in  producing  a  valuable  fiber, 
an  oil  which  now  seems  indispensable  as  a  constituent 
of  paint  and  a  high  class  stock  food.  Flaxseed,  of 
which  the  annual  production  in  this  country  averages 
about  twelve  million  tons,  contains  a  very  high  per- 
centage of  oil,  ranging  in  the  analyses  so  far  made 
from  22  to  40  per  cent.  The  average  is  variously 
stated  by  different  compilers  at  from  33  to  37  per  cent, 
and  the  mean  of  these  two  numbers  is  probably  fairly 
correct.  On  this  basis  a  bushel  of  flaxseed,  weighing 
fifty-six  pounds,  contains  nineteen  and  one- half  pounds 
of  oil  and  thirty -six  and  one -half  pounds  of  other 
substances. 

Linseed  oil  is  obtained  from  the  seed  by  both  the 
pressure  and  extraction  methods.  The  oldest  method 
was  to  subject  the  cold  crushed  seeds  to  a  heavy  pres- 
sure, which  expressed  from  70  to  80  per  cent  of  the 
oil,  leaving  a  cake  containing  from  10  to  15  per  cent. 
Later  the  warm  pressure  process  was  introduced,  which 
consists  of  moistening  the  crushed  seed,  heating  it  to 
from  160°  to  180°  Fahr.,  and  submitting  it  to  a  pressure 
of  2,000  to  3,000  pounds  per  square  inch.  This  im- 
provement  increased  the   output  of   oil    from   a  given 


246  The  Feeding  of  Animals 

quantity  of  seed,  the  amount  exp-ressed  being  about 
90  per  cent  of  the  whole,  leaving  a  cake  containing 
from  6  to  7  per  cent.  The  latest  and  most  effective 
process  is  the  extraction  of  the  oil  by  a  light  naphtha. 
The  seed  is  crushed  and  heated  as  in  the  warm  pres- 
sure method,  and  the  oil  is  then  extracted  by  repeated 
leachings  with  naphtha  until  the  residue  when  dry 
contains  only  about  3  per  cent  of  oil.  The  naphtha  is 
thoroughly  driven  from  this  residue  with  steam  so  that 
the  resulting  meal  is  entirely  free  from  odor  and  is  as 
palatable  as  the  residue  from  the  pressure  process. 

The  terms  "old  process"  and  "new  process"  are 
now  applied  to  linseed  meal,  the  former  referring  to 
that  made  by  the  cold  and  warm  pressure  processes 
and  the  latter  to  the  residue  from  naphtha  extraction. 
The  composition  differences  between  the  two  is  seen 
in  the  following  average  of  several  analyses  of  each 
kind  which  were  made  by  Woll  : 


Water 

% 

Ash 

% 

Protein 

% 

Nitrogen- 
free 
Fiber  extract 

%           % 

Pat 

% 

.9.4 

5.4 

35.6 

7.1       35. 

7.5 

.  9.2 

5.4 

36  6 

8.6       37. 

3.2 

Old  process  linseed  meal. 
New  process  linseed  meal . .  9.2 

These  averages  show  1  per  cent  more  protein  and 
3  per  cent  less  fat  in  the  new  process  meal. 

The  old  process  samples  analyzed  by  Woll  were 
doubtless  from  the  w\arm  pressure  methods  and  do  not 
fairly  represent  the  linseed  which  was  found  in  the 
markets  when  it  first  came  into  general  use.  Four 
hundred  and  twenty -eight  analyses  of  old  process  cake 
compiled  by  Dietrich  and  Konig,  which  were  made  pre- 
vious to  1888,  show  an  average  of  only  28.6  per  cent 


Linseed  Meal  247 

of  protein  and  10.6  per  cent  of  fat.  An  average  by 
the  same  authors  of  179  analyses  of  the  meal  shows 
30  per  cent  of  protein  and  9.9  per  cent  of  oil,  those 
samples  taken  previous  to  1880  being  poorer  in  pro- 
tein and  richer  in  fat  than  those  analyzed  after  that 
date.  The  average  of  twelve  samples  of  linseed  cake 
made  prior  to  1883  and  compiled  by  Jenkins,  gives 
29.7  per  cent  of  protein  and  11.2  per  cent  of  fat. 
There  is  no  question  but  that  the  meal  now  found  in 
the  markets  is  considerably  richer  in  protein  and 
poorer  in  fat  than  that  with  which  American  farmers 
were  first  acquainted. 

The  relative  values  of  the  old  and  new  process 
meals  are  much  discussed.  Many  farmers  are  preju- 
diced in  favor  of  the  former,  possibly  because  any- 
thing which  has  been  treated  chemically  is  regarded 
with  suspicion  when  considered  as  a  food.  No  good 
evidence  exists,  however,  that  new  process  meal  is  less 
palatable  or  less  healthful  than  the  old  process  prod- 
uct, nor  has  practice  demonstrated  that  in  a  general 
way  it  is  less  nutritious. 

A  very  useful  inquir}'  by  Woll  into  the  charac- 
teristics of  the  two  kinds  of  meal  showed  certain 
differences  which  are  interesting  in  this  connection. 
Two  points  were  studied  :  the  digestibility  and  the 
property  of  swelling  to  a  mucilaginous  condition  when 
stirred  up  with  water.  Experiments  with  animals  both 
in  Germany  and  in  this  country  have  shown  a  quite 
uniformly  lower  coefficient  of  digestibility  for  the  pro- 
tein of  the  new  process,  than  for  the  old  process,  meal. 
Woll  tested   this  matter  bv   artificial  dierestion  with  a 


248  The  Feeding  of  Animals 

solution  of  pepsin,  and  his  results  verified  those  se- 
cured with  animals,  the  protein  of  the  old  process 
samples  proving  to  be  10  per  cent  the  more  soluble. 
This  difference  is  believed  to  be  caused  by  the  addi- 
tional cooking  with  steam  which  attends  the  driving 
out  of  the  naphtha  from  the  new  process  meal,  for  it 
seems  to  be  well  proven  that  the  digestibility  of  vege- 
table protein  is  diminished  b}^  cooking.  American 
experiments  do  not  indicate  a  lower  digestibility  of 
total  dry  matter  for  the  new  process  meal,  which  is 
contrary  to  the  verdict  of  German  digestion  trials. 

The  property  of  swelling  to  a  mucilaginous  condi- 
tion is  one  well  known  to  pertain  to  flaxseed.  This 
is  due  to  mucilage  cells  found  in  the  seed-coat.  When 
this  mucilaginous  matter  has  once  been  swollen,  it  will 
not  repeat  the  process  after  drying.  WoU's  tests 
showed  that  the  old  process  meal  responded  to  the 
swelling  test,  but  not  the  new  process,  a  result  due 
probably  to  the  steam  cooking  of  the  latter.  This 
may  serve  as  a  means  of  determining  the  method  used 
in  manufacturing  a  given  lot  of  meal,  but  probably  has 
no  special  significance  as  to  feeding  value,  unless  it 
indicates  the  new  process  meal  to  be  less  useful  in 
making  a  porridge  for  feeding  calves 

CHEMICAL    DISTINCTIONS    IN    CATTLE    FOODS 

The  classes  of  cattle  foods  as  arranged  in  the  pre- 
vious discussion  have  had  reference  to  several  factors, 
chieflj^  those  relating  to  origin  and  texture.  Chemical 
facts  have  not  been  considered  in  these  divisions.    There 


How    Caffle  Foods  Differ  249 

are,  however,  certain  chemical  differences  among  the 
various  groups  of  feeding  stuffs,  a  knowledge  of  which  is 
helpful  in  selecting  materials  for  compounding  rations. 

Coarse  foods  vs.  grains  and  grain  products. — In  com- 
paring hays,  straws,  and  other  fodders  with  grains 
and  grain  products  there  are  points  of  chemical  uu- 
likeness  which  bear  an  important  relation  to  problems 
of  nutrition.  In  the  first  place,  the  nitrogen  com- 
pounds differ.  In  the  grains  we  find  the  nitrogen 
combined  mostly  in  the  form  of  albuminoids,  while  in 
the  fodders  a  proportion  of  it,  and  sometimes  quite  a 
large  one,  exists  iu  amides.  This  is  a  point  in  favor 
of  the  grains,  for,  as  we  have  seen,  the  nutritive 
function  of  amides  is  probabh'  more  limited  than  that 
of  albuminoids.  Again,  the  non-nitrogenous  material 
of  the  grains  is  in  general  superior  to  that  of  the  her- 
baceous cattle  foods.  In  the  former,  especially  in  the 
cereal  grains,  there  is  but  little  fiber  and  the  nitrogen - 
free  extract  is  made  up  largely  of  starch  and  other 
bodies,  whose  net  value  in  nourishing  an  animal  is 
quite  surely  greater  than  that  of  fiber  and  gums  found 
in  such  abundance  in  the  hays  and  otlier  fodders. 
The  work  of  digesting  fiber  and  gums  is  greater  than 
with  sugar  or  starch,  and  of  the  digested  material  from 
the  former  we  cannot  affirm  an  equal  value  with  that 
coming  from  the  more  easily  soluble  carbohydrates. 
In  short,  the  terms  protein  and  nitrogen -free  extract 
do  not  signify  the  same  compounds  or  the  same  values 
when   applied  to  different  feeding  stuffs. 

Classification  according  to  tlie  proportions  of  nu- 
trients. — The    relative    proportion    of    nitrogenous    and 


250  The  Feeding  of  Animals 

11  on -nitrogenous  compounds  in  feeding  stuffs  is  greatly 
varied.  There  is  no  fixed  proportion  in  the  same  spe- 
cies, even,  but  it  varies  to  some  extent  with  the  season, 
period  of  cutting,  and  other  conditions.  At  the  same 
time,  there  are  differences  of  composition  between  several 
groups  of  feeding  stuffs  that  are  constant  within  not 
very  wide  limits,  and  which  it  is  important  to  recognize. 

There  are  a  few  terms  that  are  popularly  used  to 
differentiate  feeding  stuffs  which  are  misleading.  For 
instance,  corn  meal  is  often  spoken  of  as  "carbona- 
ceous" in  contrast  to  cottonseed  meal,  which  is  called 
"nitrogenous."  It  may  be  seen  by  reference  to  pre- 
ceding data  that  there  is  a  higher  proportion  of  carbon 
in  albuminoids  than  in  starch  or  sugars.  Cottonseed 
meal  is  more  carbonaceous  than  corn  meal,  rather  than 
less  so.     Such  a  distinction  is  therefore  absurd. 

"Heat  forming"  is  another  term  often  applied  to 
foods  rich  in  carbohydrates,  while  the  more  highly 
nitrogenous  materials  are  characterized  as  "muscle 
forming,"  a  distinction  apparently  based  upon  the  facts 
that  carbohydrates  are  usually  largely  burned  in  the 
animal  body,  and  that  albuminoids  are  the  only  source 
of  the  muscle  compounds.  But,  as  a  matter  of  fact, 
the  potential  heat  value  of  the  digestible  part  of  an 
oil  meal  is  certainly  as  great  as  that  of  digestible 
corn  meal.  Under  certain  conditions  one  feeding  stuff 
is  no  more  fully  used  than  the  other  for  tissue -forming 
purposes,  and  both  may  be  wholly  utilized  in  the  pro- 
duction of  some  form  of  energy,  ultimately  heat,  the 
potential  value  of  the  oil  meal  being  no  less  in  this 
respect  than  that  of  the  corn  meal. 


Classes  of  Feeding  Stuffs  251 

The  satisfactory  division  of  feeding  stuffs  into  as 
few  as  two  classes,  according  to  their  composition,  is 
not  possible  by  the  use  of  any  terms  whatever.  Such 
a  division  is  necessarily  based  upon  the  relation  in 
quantity  of  the  protein  to  the  non- nitrogenous  part, 
and  there  is  an  almost  uniform  gradation  of  foods  in 
protein  content  from  those  containing  the  least  to 
those  most  highly  nitrogenous.  Anj'  division  into 
groups  with  reference  to  the  percentage  amount  of 
protein  must  be  entirely  arbitrary  and  should  take 
account  of  at  least  four  classes  of  materials,  other- 
wise the  extremes  of  each  division  are  too  widely 
apart.  Probably  no  more  convenient  and  rational  class- 
ification of  grains  and  grain  products  can  be  suggested 
than  the  one  proposed  by  Lindsey; 

Class  I.  Thirty  to  45  per  cent  protein,  30  to  45  per 
cent  carbohydrates.  The  oil  meals  and  gluten 
meals,  the  latter  of  which  are  represented  by  the 
Chicago,  King,  Cream,  and  Hammond. 
Class  II.  Twenty  to  30  per  cent  of  protein,  60  to 
70  per  cent  carbohydrates.  Gluten  feeds,  in- 
cluding the  Buffalo,  Golden,  Diamond,  Daven- 
port, Climax,  Joliet,  and  Standard  as  now 
made,  Atlas  meal,  dried  brewer's  grains,  malt 
sprouts,  buckwheat  middlings,  and  beans  and 
peas. 
Class  III.  Fourteen  to  20  per  cent  protein,  70  to  75 
per  cent  carbohydrates.  Wheat  brans  and  mid- 
dlings, rye  bran,  mixed  feeds  or  any  mixtures 
of  oat  feed  reinforced  bj^  more  highly  nitrog- 
enous material. 


252  The  Feeding  of  Animals 

Class  IV.  Eight  to  14  per  cent  protein,  75  to  85 
per  cent  carbohj^drates.  Barley,  corn,  oats,  rye, 
wheat,  cerealine,  hominy,  oat  feeds,  corn  and 
oat  chop,  and  corn  bran.  The  hays  and  other 
fodders    properly   belong   with  Class  IV. 

By  reference  to  these  gronps  it  is  possible  to  ascer- 
tain about  what  place  a  particular  feeding  stuff  will 
take  in  making  up  a  ration,  for  instance,  to  what  ex- 
tent it  will  serve  as  a  protein  amendment  to  a  mixture 
of  materials  composed  largely  of  carbohydrates. 

FOODS     OF    ANIMAL     ORIGIN 

The  principal  materials  of  animal  origin  that  are 
used  in  feeding  domestic  animals  are  milk,  dairj-  by- 
products and  offals  from  slaughter-houses.  The3^  are 
mostly  characterized  by  their  large  relative  proportion 
of  protein  and  their  high  rate  of  digestibility.  The 
net  nutritive  value  of  their  solid  matter  is  very  high, 
because  it  is  practically  all  utilized  and  a  minimum 
amount  of  energy  is  required  for  its  mastication  and 
digestion.  Practice  has  long  recognized  the  peculiar 
efficiency  of  feeding  stuffs  of  this  class,  which  is  due 
to  the  directly  available  forms  of  the  nutrients. 

Milk. — Whole  milk  has  a  greatly  varying  food  value 
according  to  its  proportion  of  solid  matter.  Its  com- 
position is  determined  by  several  factors.  The  milks 
of  different  species  of  domestic  animals  are  greatly 
unlike  both  in  their  proportions  of  total  solids  and  in 
the  relation   in  quantity  of  the  different  constituents. 

The   table   of   composition  of   the    milk    of   several 


Milk  of  Various  Species  253 

species,  including  human  milk,  given  herewith,  is  taken 
mostly  from  figures  given  in  Richmond's  Dairy  Chem- 
istry : 

Composition   of   the    milk   of  mammals   {per  cent) 

Species           Water     Drj^  matter    Ash  Casein     Albumin  Sugar  Fat 

Bitch 75.44        24.54       .73  6.10         5.05       3.09  9.57 

Ewe 79.40         20.56       .97  5.23         1.45       4.28  8.63 

Sow 84.04         15.96     1.05  7.23  3.13     4.55 

Goat 86.04         13.96       .70       3.49  .86       4.22     4.63 

Cow* 87.10         12.90       .70  3.20  5.10     3.90 

Woman 88.20         11.80       .20       1.  .50       6.80     3.30 

Mare 89.80         10.20       .30  1.84  6.89     1.17 

The  milks  are  arranged  in  the  order  of  their  rich- 
ness, the  dry  matter  present  varying  from  24.54  per 
cent  to  10.20  per  cent.  Those  containing  a  high  pro- 
portion of  total  solids,  particularly  those  from  the 
bitch  and  the  ewe,  are  especially  rich  in  proteids  and 
fat,  the  percentages  of  sugar  being  less  than  half  those 
in  the  poorer  milks.  It  is  noteworthy  that  the  pro- 
portions of  proteids  and  fats  in  the  milk  decrease,  and 
the  percentage  of  sugar  increases,  as  the  total  solids 
diminish.  Two-thirds  of  the  solids  of  mare's  milk  is 
sugar,  the  proportion  of  this  constituent  in  the  dry 
matter  of  a  ewe's  milk  being  only  about  one -eighth. 

If  we  assume  that  the  milk  of  each  species  is  best 
adapted  to  its  own  progeny,  it  follows  that  when  the 
young  of  other  species  is  fed  the  -milk  of  the  coav,  as 
is  so  often  done,  this  milk  should  be  modified  so  far 
as  possible  to  simulate  that  provided  under  natural 
conditions.      When,  for  instance,  cow's  milk  is  fed  to 

*  Vau  Slyke. 


254  The  Feeding  of  Animals 

a  colt,  it  should  be  diluted  and  have  its  content  of 
milk  sugar  increased;  or  when  lambs  are  given  cow's 
milk  it  may  well  be  made  richer,  by  the  addition  of 
cream,  perhaps.  The  milk  of  the  cow  varies  with  the 
breed,  the  individual  and  the  period  of  lactation,  and 
in  its  use  for  feeding  purposes  these  variations  should 
be  considered.  While  we  have  little;  or  no  data  on 
the  subject,  it  is  probable  that  the  same  causes  op- 
erate in  affecting  the  milk  of  all  species. 

Dairy  by -products.  —  These  by-products  are  three 
in  number,  skim -milk  both  from  the  gravity  and  the 
separator  processes,  buttermilk,  and  whey.  Their  aver- 
age composition,  as  taken  from  compilations  by  several 
authors,  is  as  follows: 

Composition    of  dairy    offals    {per   cent) 

Total  Casein  and 

Water      solids     Ash    albumin     Sugar  Fat 

Skim  milk,  general  average,  Cooke... 90.25  9.75  .80  3.50  5.15  .30 

Skim-milk,  gravity,  Fleischman 89.85  10.15  .77  4.03  4.G0  .75 

Separator-milk,  Richmond 90.50  9.50  .78  3.57  4.95  .10 

Buttermilk,  Cooke 90.50  9.50  .70  3.  5.30*  .50 

Buttermilk,  Vieth 90.39  9.61  .75  3.00  4.06t  .50 

Whey,  Cooke 92.97  7.03  .60  .93  5.  .50 

Wliey,  Van  Slyke 93.07  6.93  .60t  .83  5.16  .34 

Skim -milk  and  buttermilk  are  not  greatly  unlike 
ill  richness  in  solid  matter  or  in  general  composition. 
In  case  the  skim -milk  is  sweet,  buttermilk  differs 
from  it  because  in  the  latter  the  sugar  has  changed 
partially  or  wholly  to  lactic  acid.  Whey  is  considera- 
bly poorer  in  solids  than  the  other  dairy  by-products 
and  also  differs  from  them  in  the  proportions  of  the 
several  constituents. 

*  Probably  iucludts  the  lactic  acid.     t.80  per  cent  lactic  also  present.     J  Assumed. 


Dairy  By-products  as  Foods  255 

Skim -milk  is  the  residue  left  after  removing  the 
cream.  It  differs  in  composition  according  to  the 
composition  of  the  original  whole  milk  and  the  thor- 
oughness of  the  creaming.  The  percentage  of  solids 
which  it  contains  is  proportional  in  a  general  way  to 
the  richness  of  the  whole  milk.  At  one  time  a  con- 
trary notion  prevailed  and  the  skimmed  milk  of  the 
butter  breeds,  especially  the  Jersey  and  the  Guernsey 
cows,  was  popularly  supposed  to  be  of  inferior  quality. 
Numerous  analyses  have  been  made  of  this  b}'- product 
from  several  breeds,  and  the  succeeding  figures  give 
the  proportion  of  solids  and  fat  in  skimmed  milk  from 
the  gravity  process: 

Skimmed  milk 
Solids  in  Total 

■whole  milk         solids  Fat 

%  %  % 

Holstein 12.22  9.50  .52 

Ayrshire 12.98  10.40  .85 

Jersey 15.24  10.50  .37 

These  figures  show  most  clearly  that  the  Jersey 
product  is  more  valuable  than  that  from  Holstein  cows, 
volume  for  volume. 

Skim -milk  is  also  affected  by  the  manner  or  thor- 
oughness with  which  the  cream  is  removed.  The  more 
perfectly  the  fat  is  taken  out  the  less  the  percentage 
of  solids  left  behind  and  the  less  their  unit  value  as 
a  source  of  energy.  For  these  reasons  gravity  process 
skimmed  milk  is  often  more  valuable  for  feeding  than 
that  from  the  separator,  though  under  the  best  con- 
ditions of  skimming  in  both  cases  the  difference  is 
small. 

Buttermilk,  which   is    the   residue   after   extracting 


256  The  Feeding  of  Animals 

butter  from  cream,  varies  in  composition  from  such 
causes  as  the  composition  of  the  cream  and  the  per- 
fectness  of  the  churning.  The  more  fat  is  left  in  it 
the  more  it  is  worth  for  feeding  purposes.  Its  feeding 
vahie  is  but  little  less  than  that  of  skim -milk. 

Whey  solids  are  mostly  sugar.  In  good  cheese- 
making  practice,  whey  retains  scarcely  any  of  tlie 
casein  and  fat  of  the  milk.  It  therefore  takes  a  place 
in  the  ration  quite  different  from  that  of  skim-milk, 
as  it  is  essentially  a  carbohydrate  food. 

The  dairy  offals  are  peculiarly  valuable  as  food 
for  young  animals  and  swine.  It  is  safe  to  say  that 
for  calves  and  pigs  no  other  sufficiently  inexpensive 
materials  can  fully  take  their  place  in  their  relation 
to  health  and  vigor. 

Slauf/Jiter  -  house  and  other  animal  refuses.  —  The 
offals  from  slaughter  -  houses  and  from  fish,  which 
have  a  somewhat  limited  use  in  feeding  domestic  ani- 
mals, are  meat  scraps,  meat  meal,  dried  blood,  and 
dried  and  ground  fish.  The  accompanying  analyses 
display  their  composition,  which  is  subject  to  great 
variations : 

Composition   of  slaughter-house   and    other    refuses    {per   cent) 

Animal  meal,  N.  Y.  station 
Meat  meal,  German  analysis. .   10.7 
Fish  scrap,  German  analysis.   13.9 
Dried  blood,  Henry 

The  meat  and  fish  offals  vary  greatly  according  to 
proportion  of  bone  which  they  contain.  The  percen- 
tage of   protein    is    always    large,  nevertheless.     Dried 


Water 

Ash 

Protein 

Fat 

o  o 

38.7 

37.5 

13.2 

10.7 

4.1 

71.2 

13.7 

13.9 

31.3 

48.4 

6.4 

8.5 

4.7 

84.4 

2.5 

Feeding  Stuffs  of  Animal   Origin  257 

blood  is  much  less  rich  in  mineral  matter  and  fat 
than  other  slaughter-house  offals  are  generally,  and 
the  proportion  of  protein  is  correspondingly  larger. 
All  these  materials  are  excellent  poultry  foods  when 
used  as  a  part  of  the  ration.  They  may  be  fed  to 
swine  also  as  an  amendment  to  cereal  grains  when 
dairy  by-products  are  not  available. 


CHAPTER  XVII 

THE  PRODUCTION  OF  CATTLE  FOODS 

The  farmer,  in  deciding  what  forage  and  grain 
crops  lie  shall  grow,  should  take  into  consideration 
several  factors,  of  which  the  following  are  the  main 
ones:  (1)  the  adaptability  of  the  various  crops  to  the 
soil  and  climate;  (2)  the  adaptability  of  the  various 
crops  to  the  kind  of  business  which  is  to  be  followed, 
whether  dairying,  stock- growing  or  sheep  husbandry; 
(3)  the  capacity  of  the  various  crops  for  the  produc- 
tion of  digestible  food;  (4)  the  protein  supply;  (5) 
the  maintenance  of  fertility. 

1.  Concerning  the  adaptability  of  crops  to  the  great 
variation  of  soil  and  climate  in  this  countr^^  it  is  not 
possible  to  treat  extensively  in  this  connection  without 
going  too  fully  into  questions  of  agricultural  botany. 
There  are,  however,  a  few  general  facts  worthy  of  men- 
tion. In  the  first  place,  few  farmers  have  accurate 
information  concerning  the  species  of  grasses  which 
are  growing  on  their  farms.  Only  occasionally  is  one 
found  who  carefully  observes  what  species  are  most 
prosperous  under  his  conditions.  This  is  equivalent 
to  the  statement  that  but  little  attention  is  given  to 
the  matter  of  the  adaptability  of  forage  plants  to  the 
environment  under  which  they  must  be  grown.     While 

(258) 


The   Selection   of  Crops  259 

it  may  be  said  that  nature  carries  on  for  the  farmer 
more  or  less  of  a  selective  process,  it  must  be  remem- 
bered that  the  rotation  of  crops,  involving  of  necessity 
an  artificial  selection  of  species,  interferes  with  this 
process.  The  old  practice  of  maintaining  mowing 
fields  for  ten  to  twenty  j'ears  without  breaking  the  sod 
might  allow  the  grasses  most  congenial  to  the  soil  and 
climate  to  establish  themselves,  but  successful  farming 
on  this  basis  is  now  scarcely  possible.  It  is  essen- 
tial, therefore,  especially  in  dealing  with  meadows  and 
pastures,  to  know  Avhat  members  of  the  grass  family 
or  other  forage  plants  find  the  environment  congenial. 

It  is  commonly  remarked,  with  much  reason,  that 
more  is  to  be  gained  by  the  proper  selection  and  proper 
care  of  the  forage  crops  which  have  maintained  suc- 
cessful, though  perhaps  unrecognized,  existence  among 
us  for  years,  than  by  seeking  for  better  results  from 
some  introduced  species.  No  cultivated  plant  pos- 
sesses qualities  that  will  defend  the  farmer  against  the 
evil  effects  of  poor  or  ill-directed  culture,  and  when 
intelligent,  thorough  methods  prevail,  many  of  the 
familiar  species  will  do  for  us  all  we  can  reasonably 
expect.  Occasionally  an  introduced  species  may  serve 
a  useful  purpose,  as  is  true  of  alfalfa,  but  in  general  a 
more  economical  production  of  cattle  foods  will  be 
reached  most  surely  through  an  improvement  of  meth- 
ods in  growing  what  w^e  already  have. 

2.  It  is  obvious  that  the  home  production  of  feed- 
ing stuffs  must  be  adapted  to  the  kind  of  stock  kept. 
A  herd  of  good  dairy  cows  can  hardly  be  most  suc- 
cessfully managed  on  the  old  basis  of  exclusive  pastur- 


260  The  Feeding  of  Animals 

iiig  in  the  summer  and  exclusive  dry  food  in  the 
winter.  To  attain  the  best  results  the  pasture  must 
be  amended  by  soiling  crops,  at  least  during  late  sum- 
mer and  early  autumn,  and  a  succulent  food  is  a  de- 
cided improvement  to  a  winter  ration.  On  the  other 
hand,  the  successful  growing  of  steers,  sheep  or  horses 
requires  in  many  localities  only  a  good  pasture  and 
plenty  of  dried  fodder  and  grain,  although  some  suc- 
culent foods  are  desirable  with  any  class  of  animals. 
Every  feeder,  no  matter  what  his  line  of  business, 
should  have  at  command  quite  a  variety  of  fodders. 

3.  The  productive  capacity  of  the  different  crops 
used  as  cattle  foods  is  greatly  unlike.  A  satisfactory 
crop  of  maize  or  alfalfa  contains  greatly  more  dry 
matter  per  acre  than  one  of  oats,  peas,  or  any  of  the 
usual  meadow  grasses,  and  in  order  that  land  may 
yield  a  maximum  supply  of  feeding  stuffs  it  is  neces- 
sary to  step  outside  grass  and  grain  farming,  where 
long  rotations  are  practiced  and  where  a  major  part  of 
the  farm  is  kept  in  meadow  grasses  and  only  small 
areas  are  devoted  to  cultivated  crops.  Rapid  rota- 
tion and  the  use  of  the  more  grossly  feeding  crops 
are  necessary  to  a  vigorous  development  of  the  re- 
sources of  any  land  for  the  maintenance  of  animal 
husbandry. 

Other  things  being  equal,  the  most  desirable  crop 
is  the  one  producing  the  largest  amount  of  digestible 
dry  matter.  This  will  not  be  the  same  crop  for  all 
localities.  In  one  section  it  may  be  maize,  in  another 
alfalfa,  or  in  another  roots.  The  selection  must  be 
determined   by  circumstances,   and  no  rule  of  general 


Productive   Capacity   of  Different   Crops         261 

application  is  possible.  Of  course,  other  things  out- 
side of  .quantitj'  of  production  are  not  generally  equal. 
The  cost  of  production  varies  so  that  the  largest  j  ield- 
ing  crop  is  not  necessarily  the  most  economical.  This 
is  a  local  matter  also,  concerning  which  no  safe  gen- 
eral statement  can  be  made.  It  would  be  convenient 
if  some  correct,  universal  standards  of  production  and 
cost  could  be  formulated  for  the  guidance  of  farmers, 
but  both  growth  and  cost  are  much  modified  by  lo- 
cality and  other  circumstances,  and  data  are  not  avail- 
able, and  doubtless  never  will  be,  from  which  useful 
averages  may  be  obtained. 

The  most  that  it  is  possible  to  show  is  the  rela- 
tive productive  capacity  of  different  crops  when  the 
yield  is  what  is  regarded  as  highly  satisfactory  in  fa- 
vorable localities  under  good  culture.  This  is  done  in 
the  accompanying  table.  Attention  is  again  called 
to  the  fact  that  judgment  should  be  based  upon  the 
amount  of  digestible  dry  matter  produced  : 

Drj'  Digestible 

*    Yield  Dry  mat-  dry 

per  acre  matter  ter  matter 

fresh  ma-  Dry  per  digesti-  per 

terial  matter  acre  ble  acre 

lbs.  i  lbs.  i  lbs. 

Alfalfa 35,000  25  8,750  69  5,162 

Maize,  whole  plant 30,000  25  7,500  61  5,025 

Red  clover,  about  33^  tons  new  hay..     18,000  30  5,400  57  3,070 

Oats  and  peas 20,000  16.2  3,240  65  2,106 

Timothy,  about  2%  tons  new  hay 11,500  38.4  4,416  57  2,517 

Hungarian  grass 19,000  25  4,750  67  3,182 

Mangolds 60,000  10  6,000  88  5,200 

Sugar  beets 32,000  20  6,400  88  5,632 

Potatoes 18,000  25  4,500  85  3,825 

The  estimates  here  given  may  not  coincide  with  the 
views    of   all  as    to  what   constitutes  a  fair  crop,  but 


262  The  Feeding  of  Animals 

from  the  data  shown,  any  one  can  easily  make  a  cal- 
culation on  the  basis  of  his  own  estimate. 

The  foregoing  figures  emphasize  the  relative  high 
productivity  of  alfalfa,  maize  and  roots,  as  compared 
with  certain  cereal  grains  and  the  meadow  grasses. 
The  former  crops  fill  an  important  place  in  intensive 
stock  husbandry.  Probably  no  species  of  forage  plants 
are  known  that  are  more  economical  sources  of  high  class 
cattle  food  than  alfalfa  and  maize.  While  no  more 
productive  than  mangolds  and  sugar  beets  when  these 
are  at  their  best,  the  former  cost  much  less  in  labor. 

Crops  of  such  large  productive  capacity  are  espe- 
cially adapted  to  dairymen  located  on  limited  areas  of 
high-priced  land.  They  occupy  a  place  in  intensive 
culture  which  will  become  more  and  more  important 
as  grazing  and  long  rotations  are  replaced  by  soiling 
and  stable  feeding  during  the  entire  year. 

4.  The  protein  supply  of  the  farm  may  be  aug- 
mented by  the  growth  of  leguminous  crops,  such  as 
peas,  beans,  alfalfa  and  the  clovers.  In  so  far  as  climate 
and  soil  permit  the  economical  production  of  this  class 
of  fodders,  there  will  be  a  correspondingly  less  neces- 
sity for  the  purchase  of  nitrogenous  feeding  stuffs. 

5.  The  leguminous  crops  are  regarded  as  sustaining 
an  important  relation  to  fertility  in  acting  as  nitrogen- 
gatherers,  and  for  this  reason  they  are  believed  to  be 
a  valuable  adjunct  of  any  system  of  farming.  Just' 
what  proportion  of  the  nitrogen  in  a  crop  of  clover, 
for  instance,  comes  from  outside  the  soil  is  not  known, 
however,  either  for  particular  conditions  or  as  to  the 
average. 


Importance  of  Soiling   Crops  263 

SOILING     CROPS 

The  production  of  green  crops  as  an  amendment  to 
the  pasture,  or  as  a  substitute  for  it,  is  a  practice  essen- 
tial to  the  highest  success  in  dairying  on  many  farms, 
and  is  to  some  extent  desirable  in  other  branches  of 
stock  husbandry. 

There  are  few  pastures,  perhaps  none,  that  afford 
grazing  in  August  and  September  of  such  a  quality  as 
to  maintain  a  satisfactory  flow  of  milk.  In  many 
instances,  moreover,  farmers  owning  a  limited  area  of 
high-priced  tillable  land  wish  to  keep  the  maximum 
number  of  animals  per  acre,  and  to  do  this  they  must 
cultivate  soiling  crops  for  stable  feeding. 

It  is  no  longer  a  debatable  question,  whether  or  not 
soiling  is  profitable  under  most  conditions.  Unlimited 
testimony  can  be  furnished  showing  the  great  gain 
from  every  point  of  view  of  even  partial  soiling  as  an 
amendment  to  the  pasture.  Whether  soiling  should  be 
substituted  entirely  for  grazing  is  a  business  matter 
which  should  be  decided  according  to  the  conditions 
involved. 

New  England  farmers  owning  upland  rocky  pas- 
tures in  which  grow  native  grasses  of  the  highest 
quality  for  any  class  of  animals  could  not  wisely  dis- 
card them.  Such  land  generally  absorbs  but  little  cap- 
ital, and  the  labor  of  supplying  food  by  this  method 
is  reduced  to  a  minimum.  The  case  is  different  with 
high-priced,  easily  tilled  land  located  near  good  mar- 
kets. These  conditions  call  for  intensive  farming,  and 
grazing  animals  on  permanent  pastures  is  not  a  pnrt 


264  The  Feeding  of  Animals 

of  intensive  practice.  Under  such  circumstances  the 
wisdom  of  a  soiling  system  is  clearly  indicated. 

In  the  first  place,  much  more  food  is  produced  per 
unit  of  area  by  soiling  than  by  pasturage.  Armsby 
found  that  two  soiling  crops  in  one  season,  for  instance, 
rye  followed  by  corn,  j-ielded  five  times  as  much  diges- 
tible organic  matter  as  pasture  sod,  when  the  whole 
growth  on  the  latter  was  plucked  without  waste,  the 
quantities  being,  respectively,  5,845  pounds  and  1,125 
pounds.  It  is  variously  estimated  from  observations 
in  practice,  that  three  to  five  times  as  many  animals 
can  be  supported  on  a  given  area  by  soiling  as  by 
grazing. 

Again,  grazing  is  wasteful  because  of  the  imperfect 
consumption  of  the  growth  that  is  made.  Much  grass 
is  tramped  down  and  much  is  fouled  with  dung  and 
urine.  These  facts  are  well  understood.  Other  advan- 
tages besides  economy  of  land  and  material  pertain  to 
soiling,  such  as  saving  of  fences,  comfort  of  the  ani- 
mals and  an  increased  supply  of  manure,  but  these 
factors  do  not  require  discussion  in  this  connection. 

Outside  of  considerations  previously  noted,  produc- 
tiveness especially,  the  dairy  farmer  in  selecting  soiling 
crops  must  have  regard  chiefly  to  the  number  of  ani- 
mals to  be  fed,  the  time  when  the  crops  will  be  needed, 
and  the  number  of  days  required  for  their  develop- 
ment. If  soiling  is  adopted  in  order  to  amend  the 
pasture  during  the  late  summer  and  early  fall  a  lim- 
ited number  of  crops  will  meet  the  demand.  Three 
sowings  of  peas  and  oats  in  late  Maj'  and  earlj^  June 
and  two  plantings  of  corn,  one  at  the  usual  time  and 


Kinds  and  Succession   of  Soiling   Crops         265 


one  two  weeks  later,  would  furnish  a  supply  of  green 
food  when  it  is  most  likely  to  be  needed.  If  it  is  a 
question  of  selecting  crops  for  a  system  of  complete 
soiling,  nothing  more  suggestive  can  be  offered  as 
to  species  and  succession  than  schemes  prepared  by 
Phelps  for  Connecticut,  and  by  Voorhees  for  New 
Jersey : 

Connecticut   scheme 

Approximate 
Species  of  crop  Time  of  seeding  time  of  feeding 

Winter  rye Sept.  1  May  10-20 

Winter  wheat Sept.  5-10  May  20-June  5 

Clover July  20-30  June  5-15 

Grass  (from  meadows) June  15-25 

Oats  and  peas April  10  June  25-July  10 

Oats  and  peas April  20  July  10-20 

Oats  and  peas April  30  July  20-Aug.  1 

Hungarian June  1  Aug.  1-10 

Clover,  rowen Aug.  10-10 

Soy  beans May  25  Aug.  20-Sept.  5 

Cow  peas June  5-10  Sept.  5  20 

Rowen  grass  (meadows)..  Sept.  20-30 

Barley  and  peas Aug.  5-10  Oct.  1-30 

Xew   Jersey   scheme 

Approximate 
Species  of  crop  Time  of  seeding  time  of  feeding 

Winter  rye Sept.  May  1-10 

Winter  wheat Sept.  May  10  20 

Crimson  clover. ...    Sept.  May  20-June  1 

Oats  and  peas April  1  June  1-10 

Oats  and  peas April  10  June  10-20 

Mixed  grasses Sept.  June  20-30 

Oats  and  peas May  10  July  110 

Cow  peas May  20  July  10-20 

Corn June  1  July  20-Aug.  1 

Japanese  millet June  20  Aug.  1-10 


266  The  Feeding  of  Animals 

New   Jersey    scheme — continued 

Approximate 
Species  of  crop  Time  of  seeding  time  of  feeding 

Cow  peas June  10  Aug.  10-20 

Corn June  20  Aug.  20-Sept.  1 

Soy  beans July  10  Sept.  1- 10 

Japanese  millet . .    July  20  Sept.  10-20 

Corn July  1  Sept.  20-Oet.  10 

Barley  and  peas Aug.  10  Oct.  10-20 

Barley  and  peas Aug.  20  Oct.  20-30 

The  schemes  are  not  practicable  for  all  sections  of 
the  United  States.  In  the  southern  and  western  states 
more  especially,  they  would  need  modification  to  suit 
local  conditions. 

Alfalfa  is  not  included  in  either  of  the  foregoing 
lists.  For  all  sections  where  this  plant  can  be  grown 
successfully  it  takes  first  rank  as  a  soiling  crop.  In 
portions  of  New  York,  for  instance,  in  favorable  sea- 
sons it  can  be  cut  continuously  from  about  the  middle 
of  May  until  late  in  September,  and  no  other  crop  is 
more  thoroughly  relished  by  horses  and  cattle.  It  is 
valuable  for  horses,  even  when  they  are  doing  hard 
work. 

The  area  devoted  to  soiling  crops  must  be  deter- 
mined by  the  number  of  animals  and  the  productive- 
ness of  the  land  which  is  to  be  used.  Voorhees  states 
that  seven  acres  devoted  to  the  succession  of  crops 
which  he  recommends  will  supply  twenty -five  cows 
from  May  1  to  November  1.  This  estimate  would 
hold  only  when  two  and  three  crops  are  grown  on  the 
same  land  in  a  single  season,  which  requires  a  generous 
use  of  manure  or  of  commercial  fertilizers,  or  of  both. 
The  following  are  suggestions  of  possible  rotations:- 


Rotations  of  Soiling   Crops 


267 


Winter  rye,  or  crimson  clover 

Oats  and  peas 

Soy  beans 

Oats  and  peas 

Japanese  millet 

Barley  and  peas 

Winter  rye,  or  winter  wheat 

Corn 


Winter  wheat 

Cow  peas 

Japanese  millet 
r  Oats  and  peas 
\  Cow  peas 
(  Barley  and  peas 

Crimson  clover 

Corn 


Some  writers  estimate  the  needed  area  of  soiling 
crops  on  the  basis  of  one -quarter  to  one -half  a  square 
rod  per  day  for  each  full-grown  animal,  the  smaller 
unit  applying  to  corn  and  the  larger  to  oats  and  peas, 
and  similar  crops.  All  this  must  be  a  matter  of  judg- 
ment based  upon  the  circumstances  involved. 


CHAPTER   XVIII 

THE    VALUATION   OF  FEEDING   STUFFS 

It  seems  to  be  veiy  generally  supposed  that  it  is 
possible  to  state  fixed  relative  money  values  for  feed- 
ing stuffs,  and  that  by  comparing  these  with  market 
prices  the  relation  of  value  to  cost  may  be  ascertained. 
Such  a  state  of  knowledge  is  certainly  much  to  be  de- 
sired, for  it  would  be  of  great  practical  use  to  feeders. 
For  various  reasons,  however,  it  is  not  yet  attained, 
and  there  is  little  present  prospect  that  it  will  be. 
The  establishment  of  such  relative  values  for  cattle 
foods,  as  a  whole  and  for  general  use,  is  a  much  more 
complex  matter  than  many  suppose  it  to  be,  for  it 
touches  on  one  side  some  of  the  most  profound  prob- 
lems of  physiological  chemistry,  concerning  which  we 
have  only  partial  knowledge. 

The  problem  of  assigning  values  to  the  classes  of 
nutrients  in  feeding  stuffs  may  be  approached  from 
two  directions;  viz.,  from  the  commercial  side  and 
from  the  physiological  side.  In  the  first  case,  the 
effort  would  be  to  calculate  on  the  basis  of  the  prices 
of  standard  commercial  feeds,  what  is  the  actual  pound 
cost  of  each  of  the  classes  of  nutrients,  and  thus  have 
a  means  of  ascertaining  whether  a  particular  feed  is 
selling  for  less  or  more  than  the  existing  market  con- 

(268) 


Calculating    Values  of  Feeding  Stuffs  269 

ditions  warrant.  lu  the  second  case,  the  attempt  would 
be  to  determine  the  relative  physiological  importance 
of  digestible  protein,  carbohydrates,  and  fats,  and  this 
being  done,  the  relative  agricultural  values  of  feeding 
stuffs  would  be  established  on  the  basis  of  their  com- 
position and  digestibility,  thus  providing  purchasers 
with  a  guide  for  selecting  the  materials  costing  the 
least  in  proportion   to  their  value. 

COMMERCIAL   VALUES 

Experiment  stations  have  for  many  years  published 
relative  commercial  valuations  of  the  various  brands 
of  fertilizers  that  are  in  the  market.  Why  are  we  not 
able  to  follow  the  same  course  with  cattle  foods  ?  Sim- 
ply because  of  existing  conditions.  The  dry  matter  of 
cattle  foods  is  made  up  of  ash,  protein,  carbohydrates, 
and  fats.  We  practically  ignore  the  ash  and  base  the 
value  of  a  given  food  upon  the  other  three  classes  of 
compounds,  which  are  the  same  in  number  as  the  three 
useful  ingredients  of  mixed  fertilizers.  Now  if  we 
could  find  in  the  market  a  cattle  food  supplying  only 
a  single  ingredient,  as  is  the  case  with  fertilizers,  we 
could  from  its  composition  and  market  price  determine 
the  cost  of  this  ingredient.  As  a  rule,  however,  these 
classes  of  nutrients  must  be  bought  in  a  mixed  condi- 
tion. All  commercial  cattle  foods,  except,  perhaps, 
one  waste  product  from  sugar  production,  are  mix- 
tures in  varying  proportions  of  protein,  carbohydrates, 
and  fats.  When  we  buy  one  we  buy  all  three.  Pro- 
tein, starch,  sugar  or  oils  as  found  in  commerce  have 


270  The  Feeding  of  Animals 

become,  through  the  necessary  processes  of  separation, 
too  costly  to  be  considered  for  cattle -feeding  purposes, 
and  their  prices  in  these  forms  are  not  a  proper 
basis  of  calculation.  If,  therefore,  a  farmer  pays  $15 
for  a  ton  of  wheat  bran,  what  proportion  of  this  sum 
shall  he  assign  to  the  320  pounds  of  protein,  the 
1,240  pounds  of  carbohydrates,  or  the  84  pounds  of 
fats? 

Commercially  considered  our  problem  is  complex, 
and  no  simple  process  will  solve  it.  If  we  were  to 
determine  what  is  the  cost  of  one  pound  of  dry  matter 
through  the  simple  division  of  the  price  of  a  ton  of 
feed  by  the  pounds  of  dry  matter  which  it  contains, 
and  then  declare  that  all  forms  of  dry  matter  have 
equal  cost,  we  would  get  as  many  prices  for  protein 
and  starch  as  there  are  commercial  feeds,  with  no  dis- 
tinction as  to  the  money  value  of  these  nutrients. 
Such  a  method  would  be  absurd.  It  would  be  a  bare 
assumption  to  declare  that  all  the  compounds  of  a 
food  should  have  equal  market  cost. 

An  attempt  was  made  in  Germany,  and  to  some 
extent  in  this  country,  to  calculate  by  the  "method  of 
least  squares"  what  should  be  considered  the  cost  of 
protein,  carbohydrates,  and  fats  as  based  upon  the 
ton  prices  of  a  variety  of  feeding  stuffs.  Valuations 
so  derived  appeared  to  find  favor  for  a  time,  and  some 
of  our  experiment  stations,  following  the  lead  of  Ger- 
man chemists,  published  pound  prices  for  the  three 
classes  of  nutrients,  and  calculated  what  commercial 
cattle  foods  should  cost  when  valued  on  a  common 
basis.     It  was  soon  found,  however,  that,  mathemati- 


Inaccuracies  of  Money    Valuations  271 

cally  as  well  as  practically,  most  absurd  results  were 
obtained. 

In  the  first  place,  it  is  already  demonstrated  that 
the  money  valuations  are  often  greatly  influenced  by 
the  choice  of  feeds  which  shall  enter  into  the  calcula- 
tion. Penny,  in  New  Jersey,  using  cottonseed  meal, 
bran,  middlings,  cobmeal,  corn  meal,  and  oats,  ob- 
tained certain  values  for  protein,  carbohydrates,  and 
fats.  Hill  shows  that  if  Penny  had  left  out  the  cob- 
meal  the  value  for  fat  would  be  only  half  that  found, 
and  the  value  of  the  protein  and  carbohydrates  would 
be  a  quarter  more.  Woll  obtained  certain  pound  prices 
with  a  list  of  common  feeds,  but  Hill  shows  again 
that  if  Woll  had  left  out  rye  bran  these  prices  would 
be  greatly  changed.  It  appears  that  varying  individual 
judgments  as  to  the  list  of  feeds  which  shall  determine 
values  maj^  cause  absurd  differences  in  the  calculated 
market  cost  of  the  nutrients,  and  introducing  into  the 
list  or  withdrawing  from  it  a  comparatively  unim- 
portant feeding  stuff  may  lower  or  raise  the  price  of 
one  nutrient  even  one -half. 

A  still  more  serious  difficulty  arises  from  the  fact 
that  often  when  an  apparently  typical  and  proper  list 
of  feeds  is  used  from  which  to  calculate  prices,  the 
use  of  the  method  of  least  squares  results  in  giving 
a  negative  value  to  one  of  the  nutrients.  In  several 
cases  of  this  kind  the  fat  was  shown  to  be  worth  less 
than  nothing,  a  most  absurd  conclusion.  This  mathe- 
matical method  is,  therefore,  not  available  for  the 
valuation  of  feeding  stuffs,  and  so  far  no  mathema- 
tician has  offered  one  that  is. 


272  The  Feedhuj  of  Animals 

PHYSIOLOGICAL    VALUES 

We  are  left  now  to  inquire  whether  we  may  not 
use  physiological  values,  in  other  words  the  work  which 
a  nutrient  will  perform  in  the  animal  body,  as  a  start- 
ing point  from  which  to  calculate  relative  values.  If, 
for  instance,  it  could  be  demonstrated  that  protein  has 
a  fixed  physiological  value  twice,  and  fats  three  times, 
that  of  carbohydrates,  it  would  then  be  a  very  simple 
matter  to  ascertain  what  proportion  of  tlie  cost  of  a 
ton  of  cottonseed  meal  should  be  applied  to  each  class 
of  nutrients.  To  illustrate,  a  ton  of  average  cotton- 
seed meal  contains  about  590  pounds  of  carbohydrates, 
860  pounds  of  protein,  and  260  pounds  of  fat.  If 
these  ingredients  are  assumed  to  have  a  ratio  of  value 
of  1,  2,  and  3,  then  the  whole  would  be  equivalent  to 
8,090  units  of  carbohydrates,  the  cost  of  one  unit  of 
which  would  be  .8  cent,  when  we  pay  $25  per .  ton 
for  the  cottonseed  meal.  On  this  basis  it  would  be 
necessary  to  assign  to  the  protein  a  cost  of  1.6  cents 
per  pound,  and  to  the  fats  2.4  cents.  If  our  premise 
were  correct  we  could  calculate  the  cost  of  the  nutrients 
in  any  one  of  the  feeding  stuffs,  and  could  either 
ascertain  which  was  the  cheapest  source  of  each  in- 
gredient, or  by  averaging  could  establish  a  basis  for 
a  general  valuation.  Unfortunately  no  such  a  premise 
can  be  correctly  formulated.  We  are  not  yet  wise 
enough  to  establish  fixed  relative  physiological  values 
for  the  three  classes  of  nutrients. 

It  may  be  asked,  do  we  not  know  the  heat  value  of 
a  unit  of  each  of  the  nutrients,  of  protein,  of  starch, 


Physiological    Values  not  Definite  273 

and  of  fat  ?  We  probably  do.  These  values  have 
beeu  found  with  apparent  accuracy.  Why,  then,  may 
we  not  establish  the  relative  value  of  the  nutrients 
on  the  basis  of  their  potential  energy,  w^hich  is  meas- 
ured by  the  heat  they  produce  upon  combustion  ?  Sim- 
ply because  foods  have  another  function  beside  fur- 
nishing motive  power  to  the  animal  and  keeping 
him  warm.  They  act  as  building  material.  The  pro- 
tein and  fat  of  milk  and  of  the  body  tissues  are  de- 
rived from  the  food  compounds,  and  the  actual  rela- 
tive value  of  these  compounds  for  constructive  pur- 
poses is  not  yet  known.  Xo  one  has  yet  succeeded  in 
actually  determining  the  relative  money  value  of  pro- 
tein, carbohydrates  and  vegetable  fats  as  fat  producers, 
and  we  have  no  data  that  allow  a  definite  conclusion 
concerning  the  comparative  money  worth  of  the  muscle- 
forming  function  of  protein  as  against  the  fat -forming 
function  of  stanch.  There  is  no  promising  prospect,  at 
present,  of  being  able  to  compare  foods  on  the  basis 
of  their  physiological  importance  as  a  means  of  deter- 
mining what  should  be  the  relative  market  cost. 

SELECTION  OF  FEEDING  STUFFS 

What  useful  knowledge  is  available  to  the  stock- 
feeder  as  a  means  of  guiding  him  to  an  economical 
selection  ?  In  the  first  place,  the  feeder  may  know 
the  composition  of  feeding  stuffs.  If  he  cares  to  be 
intelligent  in  his  business  he  will  know  that  some 
feeds  carry  more  nitrogenous  matter  than  others;  he 
will  be  aware  that  all  the  cereal  grains  contribute  to 


214:  The  Feeding  of  Animals 

the  ration  much  the  same  compounds  in  much  the 
same  proportions,  and  he  will  understand  the  varia- 
tions of  composition  among  the  waste  products  that 
are  in  the  market  as  commercial  feeds.  He  will  learn 
how  the  coarse  foods  differ  among  themselves  and 
from  the  grains.  Practice  and  observation  will  teach 
him  that  some  feeds  are  better  adapted  than  others  to 
a  certain  class  of  animals,  even  though  of  essentially 
the  same  composition.  In  his  efforts  to  compound 
rations  he  will  not  onh^  have  regard  for  this  adapta- 
tion, but  he  will  keep  in  mind  what  practice  and  sci- 
ence have  taught  concerning  the  mixtures  necessary 
to  secure  an  efficient  combination  of  nutrients  for  the 
work  to  be  done. 

After  all  this  is  understood,  there  may  be  several 
feeds  which  are  essentially  alike  in  composition  and 
nutritive  function  but  which  have  different  prices,  and 
there  still  remains  the  problem  of  selecting  the  most 
economical.  If  a  feeder  wishes  for  carbohydrates, 
from  what  source  should  he  purchase  them  ?  If  he 
needs  protein  should  he  select  gluten  meal,  one  of 
the  oil  meals,  or  some  other  of  the  nitrogenous  by- 
products ?  It  is  clear  that  the  best  he  can  do  is  to 
select  the  feeds  that  supply  the  largest  quantity  of 
available  nutrients  for  the  least  money.  If  all  the 
feeding  stuffs  were  digested  in  equal  proportions  there 
would  be  no  need  of  considering  digestibility,  but  this 
is  not  the  case.  Large  differences  in  digestibility  exist. 
From  86  to  88  per  cent  of  the  dry  matter  of  the 
cereal  grains,  oats  excepted,  is  dissolved  by  the  diges- 
tive juices,  while  the  solubility  of  wheat  bran,  brewer's 


Selecting  Feeding  Stnffs  275 

grains,  and  oat  feeds  is  on  the  average  only  about  62 
per  cent.  Oats  are  nearly  one-fonrtli  less  digestible 
than  corn,  barley  or  rye.  The  refuse  products  known 
as  the  oil  meals  are  less  digestible  than  the  gluten 
feeds  and  meals,  due,  doubtless,  to  the  hulls  contained 
in  the  former.  These  facts  are  important  and  affect 
the  nutritive  value  of  commercial  feeds  very  materially. 
Farmers  should  base  their  judgment  of  the  value 
of  feeding  stuffs  primarily  upon  the  i)roportions  o£ 
digestible  dry  matter  which  they  contain.  This  method 
will  probably  allow  the  closest  approximation  to  rela- 
tive values  of  any.  It  is  certainly  more  accurate  than 
a  comparison  of  the  proportions  of  total  dry  matter. 
A  hundred  pounds  of  corn  contains  even  less  dr}^ 
matter  than  the  same  weight  of  oat  feed,  but  the  di- 
gestible material  of  the  former  is  over  30  per  cent  in 
excess  of  that  in  the  latter.  It  is  to  be  remembered, 
however,  that  comparisons  of  this  kind  can  only  be 
instituted  between  feeding  stuffs  of  the  same  class. 
The  relative  values  of  oil  meal  and  corn  meal  cannot 
be  ascertained  in  this  way,  neither  can  those  of  tim- 
othy hay  and  corn  meal.  We  should  not  pay  for  oil 
meal  and  corn  meal  on  the  basis  of  the  quantities  of 
digestible  nutrients  which  they  furnish,  because  the 
nutrients  are  not  identical  in  the  two  cases.  Diges- 
tible material,  which  is  40  per  cent  protein,  cannot  be 
measured  by  digestible  material,  which  is  only  10  per 
cent  protein.  Neither  can  we  so  compare  timothy  hay 
and  corn  meal,  for  while  the  proportions  of  protein 
and  non- protein  compounds  may  not  be  so  very  differ- 
ent   in    the    two,    the    nitrogen -free    compounds    are 


276 


The  Feeding  of  Animals 


greatly    unlike    and     may   have     uulike     physiological 
values,  as  we  have  seeu. 

The  following  table  shows  the  digestible  material 
in  100  pounds  of  various  feeding  stuffs,  as  calculated 
from  average  composition  and  digestibility.  In  the 
case  of  hays  the  water  content  is  assumed  to  be  uni- 
form; viz.,  12.5  per  cent,  while  the  percentages  given 
for  the  grains  are  the  averages  found  by  analysis: 


Class  I— Dried  grass  plants 

Corn  fodder,  dent 

Corn  fodder,  flint 

Corn  fodder,  sweet 

Corn  stover 

Hungarian  hay 

Oat  straw 

Orchard  grass  hay 

Ked  top  hay 

Timothy,  all 

Timothy,  in  bloom  or  before 

Timothy,  after  bloom 

Class  II— Dried  legumes 

Alfalfa 

Clover,  alsike 

Clover,  red 

Clover,  white   

Class  III— Cereal  grains 

Barley 

Corn  meal 

Corn  and  cob  meal    

Oats 

Oat  feed 

Rye  meal 


Per  cent  of 

digestibility 

of  dry 

matter 

64 

68 
67 
57 
65 
50 
57 
60 
53 
61 
53 

59 
58 
57 
67 

86 
88 
79 
70 
62 
87 

*Assumed. 


Pounds  dry 
matter  in 
100  of  the 

feeding  stuff 

60* 

60* 

60* 

60* 

87.5 

90 

87.5 

87.5 

87.5 

87.5 

87.5 

87.5 
87.5 
87.5 
87.5 


85 
85 
89 
92 


Poiinds 

digestible 

dry  matter 

in  100  of 

feeding  stufif 

38.4 

40.8 

40.2 

34.2 

56.9 

45 

49.9 

52.5 

46.4 

53.4 

46.4 

51.6 
50.8 
49.9 
58.6 

76.5 

74.8 

67.1 

62.3 

57 

76.5 


Selecting  Feeding   Stuffs  277 

Pounds 

Per  cent  of  Pounds  dry  digestible 

digestibility  matter  in  dry  matter 

of  dry  100  of  the  in  100  of 

matter  feeding  stuff  feeding  stuff 
Class  IV— Nitrogenous  feeds 
16-30  per  cent  protein 

Brewer's  grains 62  92  57 

Gluten  feed 86  92  79. 1 

Malt  sprouts 67  90  60.3 

Wheat  bran 62  88  54.5 

Wheat  middlings 75  88  66 

Pea  meal 87  90  78.3 

Class  V— Nitrogenous  feeds 
30-45  per  cent  protein 

Gluten  meal 90  92  82.8 

Linseed  meal,  O.  P 79  91  71.9 

Linseed  meal,  N.  P 80  90  72 

Cottonseed  meal 74  92  68 

It  is  full}'  recognized  that  these  figures  cannot  be 
taken  as  absolute  relative  values.  Feeding  stuffs  bear- 
ing the  same  name  are  not  alwaj's  exactl}'  similar  in 
composition  or  in  equally  good  condition.  Variations 
in  the  moisture  content  occur,  especiallj-  with  the  coarse 
fodders.  Even  after  allowing  for  all  these  factors, 
results  will  not  follow  exactly  the  quantities  of  diges- 
tible matter  supplied,  because  there  seems  to  be  a 
greater  adaptability  of  some  feeds  to  the  needs  of  a 
particular  species.  Nevertheless  we  are  forced  to  con- 
clude that  food  materials  of  the  same  class  must  fur- 
nish energy  and  building  material  in  proportion  to 
what  is  digested  from  them. 


OTHER   STANDARDS   OF   VALUATION 


Certain  writers  and  speakers  base  the  value  of  ni- 
trogenous feeding  stuffs,  from  bran  up,  entirely  on  the 


278  The  Feeding  of  Animals 

protein  content,  and  they  divide  the  price  \>y  the 
ponnds  of  protein  in  a  ton  in  order  to  determine  the 
rehxtive  econom}"  of  purchasing  this  or  that  material, 
and  the  feeding  stuff  in  which  the  protein  cost  is  the 
least  when  so  reckoned  is  regarded  as  the  economical 
one  to  purchase.  This  method  seems  to  be  absurd,  for 
it  is  an  assumption  that  the  nutritive  value  of  the 
carbohydrates  and  fat  in  commercial  foods  may  be 
ignored.  The  argument  is  that  the  farm  furnishes 
carbohydrates  in  abundance,  and  that  commercial 
products  should  merelj-  serve  the  purpose  of  rein- 
forcing the  protein  supply.  If  the  cai-bohydrates  of 
the  farm  have  no  selling  value  then  this  argument 
has  some  force,  but  this  is  ordinarily  not  the  case. 
When  starch  and  similar  compounds  must  be  pur- 
chased as  a  necessary  accompaniment  of  protein,  thus 
causing  a  surplus  of  carbohj^drate  food,  certainly  hay, 
oats,  corn,  barley,  or  some  other  home  product  mny  be 
sold  to  relieve  this  surplus. 

Many  practical  feeding  experiments  have  been  con- 
ducted for  the  purpose  of  comparing  the  different 
grain  products  as  foods  for  the  various  classes  of 
animals.  Useful  facts  have  been  reached  in  this  way, 
especially  as  the  greater  adaptability  of  some  materials 
than  others  for  a  particular  species.  But  experiments  of 
this  kind  cannot  be  relied  upon  to  fix  relative  values  of 
feeding  stuffs  for  milk  production,  beef  production  orfoi-' 
any  other  purpose.  This  is  so,  first  of  all,  because  the 
errors  of  such  tests  are  so  large  that  we  cannot  re- 
gard their  apparent  outcome  as  establishing  constants. 
Again,  the  problems  involved  are  too  complex  and  the 


Inacatraie  Standards  of  Valuation  279 

effect  of  a  given  ration  too  dependent  upon  variable 
conditions,  to  allow  logical  conclusions  from  such  ex- 
perimental data.  The  difficulties  of  the  situation 
will  be  made  clear  to  any  one  by  a  careful  study 
of  the  whole  mass  of  data  resulting  fi«om  feeding- 
tests.  Differences  appear,  some  of  which  are  consist- 
ently in  one  direction,  especially  in  comparing  nitrog- 
enous with  carbohydrate  foods,  but  as  between  mate- 
rials of  the  same  class  their  comparative  values  as 
indicated  by  different  experiments  are  greatly  variable, 
even  contradictory.  Any  one  w^ho  endeavors  to  reach 
fixed  and  universal  valuations  on  an  experimental 
basis  of  this  kind  will  find  himself  involved  in  hope- 
less confusion. 

Once  in  a  while  some  one  talks  wildly  about  leaving 
food  valuation  to  the  "old  cow."  It  is  sometimes  con- 
sidered a  telling  argument  against  the  chemist's  wis- 
dom to  declare  that  he  and  the  old  cow  do  not  agree. 
Certainly  the  cow  knows  better  than  the  chemist  what 
she  likes  to  eat,  and  it  is  little  use  to  offer  her  foods 
she  does  not  relish.  Even  a  chemist  knows  that.  If, 
however,  a  dozen  commercial  feeding  stuffs  were  spread 
around  on  a  barn  floor  it  would  be  much  safer  to 
trust  an  agricultui-al  chemist,  especially  one  experi- 
enced in  stock  feeding,  to  select  a  ration  than  any 
cow  ever  grown,  —  Holstein,  Ayrshire,  Jersey,  long- 
horned,  dishorned,  or  what  not.  The  cow  would  prob- 
ably get  at  the  corn  meal  and  stay  with  it  until  well  on 
the  way  to  a  fatal  case  of  indigestibility.  Her  judg- 
ment is  just  about  as  good  as  that  of  a  child  with  a 
highlv  cultivated  "sweet  tooth." 


CHAPTER   XIX 

THE   SELECTION  AND    COMPOUNDING    OF  RATIONS 

There  are  several  factors  that  must  be  considered 
in  selecting  an  efficient  and  economical  ration, — factors 
which  relate  to  both  science  and  practice.  It  is  gener- 
ally desirable  that  a  food  mixture  shall  be  ''balanced," 
but  this  gives  no  assurance  that  a  ration  can  be  fed 
under  particular  conditions  with  satisfactory^  results. 
Intelligent  observation  in  the  barn  or  stable  really 
takes  the  first  place  in  formulating  a  method  of  feed- 
ing, which  is  supplemented  to  a  valuable  extent  by  the 
scientific  insight  of  the  chemist  and  physiologist. .  A 
ration  may  be  chemically  right  and  practicallj'  wTong, 
but,  at  the  same  time,  it  is  worth  much  to  the  feeder 
to  be  assured  that  the  nutrients  which  he  supplies  to 
his  animals  will  meet  their  physiological  needs.  More- 
over, commercial  relations  such  as  the  prices  of  feeds 
must  be  considered,  and  this  is  a  business  question 
and  not  a  scientific  matter. 

1.  A  successful  ration  must  be  palatable.  An 
agreeable  flavor  is  not  a  source  of  energy  or  of  build- 
ing material,  but  it  tends  to  stimulate  the  digestive 
and  assimilative  functions  of  the  animal  to  their  high- 
est efficiency,  and  is  a  requisite  for  the  consumption 
of  the  necessary  quantity  of  food.    Common  experience 

(280) 


Palatdbleness  and .  Adapt aMliUj  of  Ration       281 

teaches  that  when  cows  or  auimals  of  any  other  class 
do  not  like  their  food,  they  "do  not  do  well."  Per- 
sons sometimes  claim  that  they  have  contracted  dys- 
pepsia by  eating  food  which  is  not  relished,  even  food 
that  is  nutritious  and  well  cooked,  aud  which  would 
be  entirely  satisfactory  to  other  individuals.  The  situ- 
ation is  still  worse  when  the  food  is  undesirable  both 
as  to  texture  and  flavor.  We  have  reason  to  believe 
that  animals  are  susceptible  to  the  same  influences  as 
man,  though  perhaps  not  to  the  same  extent.  An  ani- 
mal is  more  than  a  machine,  and  is  possessed  of  a 
nervous  organism,  the  existence  of  which  should  never 
be  ignored. 

One  waj'  of  stimulating  an  animal's  appetite  is  to 
feed  a  variety  of  materials.  Continuous  feeding  on  a 
single  coarse  food  and  one  grain  is  not  conducive  to 
the  best  results.  The  various  available  fodders  and 
grains  should  be  so  combined  as  to  allow  the  feeding 
of  all  of  them  throughout  the  season  and  avoid  the 
exclusive  use  of  one  or  two  kinds  for  any  extended 
period  of  time.  The  skilful  feeder,  then,  will  not  fail 
to  make  the  ration  as  palatable  as  possible,  and  will 
always  consider  the  idiosyncrasies  of  appetite  of  each 
animal. 

2.  The  ration  must  be  adapted  to  the  species.  This 
is  obvious  as  relates  to  quantity,  but  is  equally  true  of 
the  kinds  of  materials.  For  instance,  both  poultry  and 
swine  generally  eat  cottonseed  meal  with  reluctance 
and  with  danger  to  health.  Wheat  bran  is  less  de- 
sirable for  swine  than  for  other  species.  The  horse 
and  the  hog  are  not   adapted  to  rough   fodder  as  are 


282  The  Feeding  of  Animals 

the  ruminants.  It  is  useless,  however,  to  mention  at 
this  point  other  instances  of  this  character,  or  to  com- 
ment on  their  importance,  further  than  to  emphasize 
the  foolishness  of  trjdng  to  bring  all  species  of  animals 
to  a  common  basis  in  the  supply  of  feeding  stuffs. 

3.  The  physiological  requirements  of  the  animal 
must  be  considered.  A  ration  of  maximum  physio- 
logical efficiency  and  economy  must  contain  the  several 
nutrients  in  such  quantities  and  proportions  as  will 
meet  the  needs  of  the  particular  animal  fed,  without 
waste.  This  statement  is  based  upon  facts  given  else- 
where in  this  volume  relative  to  the  demands  of  the 
animal  body  and  the  functions  of  the  nutrients. 

It  remains  now  for  us  to  consider  how  to  compound 
such  rations  as  are  desired,  or  those  that  are  adapted 
in  kind  and  quantity  to  the  requirements  which  they 
are  to  meet.  Obviously,  the  first  essential  for  doing 
this  is  the  adoption  of  standards  to  which  rations 
should  conform,  for  if  we  do  not  have  these  there  is 
no  possibilit}^  of  concluding  whether  one  food  mixture 
is  better  or  worse  than  another  for  a  particular  pur- 
pose. 

Such  standards  have  been  proposed,  which  we  knew 
first  as  German  feeding  standards.  As  found  in  the 
tables  published  by  German  authors,  they  are  the 
result  of  numerous  and  elaborate  studies  of  the  bal- 
ance of  loss  or  gain  to  the  animal  organism  when' 
rations  of  various  kinds  were  fed  to  animals  at  rest, 
at  work,  and  when  producing  meat,  wool  or  milk,  in 
desirable  quantities.  They  relate  entirely  to  physio- 
logical demands  without  reference  to  the  cost  of   the 


Feeding  Standards  283 

rations  or  to  the  profits  which  may  result  from  their 
use. 

These  standards  take  account  of  two  main  factors: 
(1)  the  quantity  of  avaikble  nutrients,  and  (2)  the 
relative  proportions  of  the  classes  of  nutrients.  Quan- 
tity is  an  essential  consideration,  for  it  is  obvious  that 
enough  energy  and  building  material  must  be  supplied 
to  do  a  given  Avork.  It  is  also  obvious  that  quantity 
must  be  a  variable  factor  according  as  the  animal  is 
large  or  small,  doing  hard  or  light  work,  giving  much 
or  little  milk,  or  fattening  rapidly  or  slowly. 

Account  must  be  made  of  the  proportions  of  the 
nutrients,  because  protein,  for  instance,  has  peculiar 
functions  which  other  nutrients  cannot  exercise,  and 
less  than  a  certain  minimum  of  the  proteids  would 
limit  production  by  just  the  amount  of  the  deficiency. 
In  order  for  the  protein  to  serve  its  maximum  useful- 
ness its  energy  should  not  be  encroached  upon  to  fill 
a  place  equally  well  or  better  taken  by  carbohj^drates ; 
consequently,  tlie  proportion  of  carbohydrates  must  also 
be  considered. 

The  relative  proportion  of  the  nutrients  of  a  ration 
we  speak  of  as  the  nutritive  ratio.  By  this  term  is 
meant  the  relation  in  quantity  of  the  digestible  pro- 
tein to  all  the  other  digestible  organic  matter  reck- 
oned in  terms  of  carbohydrates.  If  we  multiply  the 
quantity  of  fat  by  2.4  we  get  its  carbohydrate  equivalent, 
and  if  we  add  this  product  to  the  quantity  of  carbo- 
hydrates present  as  such  we  have  the  carbohydrate 
value  of  the  digestible  matter  other  than  the  protein. 
This  sum  divided  by  the  number  representing  the  pro- 


284  The  Feeding  of  Animals 

tein  gives  the  nutritive  ratio.  For  instance,  in  a  ration 
mentioned  later  there  are  .94  pound  protein,  9.65 
pounds  carbohydrates,  and  .49  pound  fat.  (.49X2.4 
+  9. 65)-^. 94  =  11.5.  1:11.5  is  therefore  the  nutritive 
ratio  of  the  ration. 

A  nutritive  ratio  may  be  designated  as  "narrow," 
"wide,"  or  "medium."  These  terms  do  not  represent 
exact  limits,  to  which  there  is  universal  agreement. 
A  narrow  ratio  is  one  where  the  proportion  of  protein 
is  relatively  large,  not  less  perhaps  than  1:5.5.  A 
wide  ratio  is  one  where  the  carbohydrates  are  very 
greatly  predominant,  or  in  larger  proportion  perhaps 
than  1:8.0.  Anything  between  1:5.5  and  1:8.0  may 
properly  be  spoken  of  as  a  medium  ratio. 

For  the  purpose  of  illustration  a  few  feeding  stand- 
ards are  given  in  this  connection.  These  are  selected 
from  standards  proposed  by  Wolff,  as  modified  by 
Lehmann.  (See  full  table  in  appendix.)  They  refer  in 
all  instances  to  animals  weighing  l;000  pounds: 

For   1,000  pounds    live   weight  (laiJy 

Total 
Diges-     Diges-  diges- 

Dry         tible       tible     Oiges-     tible  Niitri- 

siib-  pro-    earboliy-   tible    organic  tive 

slanee        tein      drates       fat      matter  ratio 

lbs.         lbs.         lbs.        lbs.         lbs. 

Cow,  yield  milk,  22  lbs...     29         2.5         13         .5         10  1:5.7 

Fattening  steer,  1st  per. ..     30         2.5         15         .5         18  1 :  G.5 

Horse,  medium  work 24         2.  11         .0         13. G       1:G.2. 

These  and  other  standards  will  be  discussed  later 
when  w^e  come  to  consider  the  feeding  of  the  various 
farm  animals.  Our  present  purpose  is  simply  to  make 
clear  the  steps  necessary  to  bringing  the  quantity  and 


Calculation  of  Standard  Rations  285 

composition  oH  the  ration  into  conformity  with  the 
standard  selected. 

As  a  means  of  showing  the  steps  involved  in  cal- 
culating what  a  ration  is,  and  how  to  improve  it  if 
necessary,  we  will  assume  that  it  is  desired  to  learn 
whether  a  food  mixture  which  a  milch  cow  is  eating 
is  what  it  should  be,  and  if  it  is  not,  how  to  make 
it  so.  The  standard  ration  for  a  1,000-pound  cow, 
giving  twenty -two  pounds  of  average  milk,  expressed 
in  terms  of  water -free  nutrients,  has  been  given  in 
the  preceding  table. 

The  first  point  which  requires  our  attention  is  that 
this  standard  is  mainly  expressed  in  terms  of  water - 
free  digestible  nutrients.  This  means  that  Ave  must 
take  into  account  the  composition  and  digestibility  of 
the  particular  feeding  stuffs  which  enter  into  a  ration 
if  we  would  discover  w^iat  it  really  is  supplying  of 
available  food  compounds.  It  is  evident  that  usually 
feeders  cannot  have  their  cattle  foods  analyzed,  and 
so  they  must  resort  to  the  tables  of  averages  of  com- 
position and  digestibility,  which  are,  or  may  be,  in  the 
hands  of  every  farmer.  But  what  figures  shall  be 
selected  for  use  ?  As  we  have  learned,  feeding  stuffs, 
especially  fodders,  differ  within  quite  wide  limits  in 
what  they  contain  and  in  what  the  animal  will  dissolve 
from  them,  according  to  the  stage  of  growth  and  con- 
ditions of  curing,  etc.,  and  an  average  percentage  ^of 
protein  or  an  average  coefficient  of  digestibility  is 
likely  to  differ  widely  from  the  actual  facts  as  per- 
taining to  a  particular  material.  All  that  can  be 
done  is  to  select  as  nearly  as  possible  the  figures  which 


286  The  Feeding  of  Animals 

have  been  found  for  feeding  stuifs  in  the  condition  of 
those  which  are  to  be  fed.  If  the  hay  is  from  mature 
grass  use  tlie  composition  percentages  aud  digestion 
coefficients  given  for  such  hay;  if  the  sikige  is  from 
mature  corn,  pursue  a  similar  course  in  this  case,  and 
so  on.  Difficulty  will  be  met  in  always  finding  suit- 
able figures,  because  without  question  there  has  been 
a  failure  to  properly  classify  tables  of  composition  and 
digestibility  on  the  basis  of  the  character  of  the  ma- 
terials. 

The  assumed  ration  which  we  wish  to  find  out 
about  consists  of 

lbs.  lbs. 

Late  cut  timothy  hay. .     10  Hominy  chops 2 

Corn  silage 25  Winter  wheat  bran.  . .     3 

The  averages  for  composition  and  digestibility, 
which  are  as  likely  as  any  to  represent  these  and  other 
materials,  are  the  following: 


-Composition •     ^Digestibility- 


it  OJ  f-OiJ  <i>  U       O  i^ 

^       CO      2        .-::     .ti «     «     2     .-2    .ti  *     rt 

Timothy  hay,  bite  cut 14.1  3.9      5.  31.1  43.7  2.2  45.  47.  60.  52. 

Clover  hay,  avevago  quality 1.').3  G.2  12.3  24.8  38.1  3.3  58.  54.  G4.  55. 

Corn  silage,  mature 79.1  1.4      1.7      6.  11.        .8  56.  70.  76.  82. 

Hominy  chops 11.1  2.5      9.8  3.8  64.5  8.3  68.  95.  92. 

Wheat  bran 11.9  5.8  10.4  9.  53.9  4.  78.  29.  69.  68. 

Lii*eea  meal,  N.  P 10.1  5.8  33.2  9.5  38.4  3.  85.  80.  86.  97. 

The  first  step  in  the  calculation  is  to  find  out  what 
percentages  of  digestible  material  the  components  of 
our  proposed  ration  contain,  and  we  shall  obtain  these 


Calculation  of  Standard  Rations  287 

b}^  multiplying  the  percentages  of  composition  by  the 
coefficients  of  digestibility  and  dividing  the  product  by 
100;  that  is,  if  timothy  hay  contains  five  per  cent  of 
protein,  45  per  cent  of  which  is  digestible,  then  forty- 
five  hundredths  of  five  will  be  the  percentage  of  diges- 
tible protein  in  the  hay.  In  this  way  the  following 
figures  were  obtained.  The  percentage  of  digestible 
carbohydrates  represents  the  sum  of  the  quantities  di- 
gested from  both  the  crude  fiber  and  the  nitrogen- 
free  extract.  Tables  are  now  published  which  show 
percentages  of  digestible  ingredients,  and  which  Avill 
render  this  calculation  largely  unnecessary: 

Total 

Digestible  digestible 

Digestible     carbohy-  Digestible  organic 

protein         drates  fat  nut;fients 

%                   %  %  % 

.  Timothy  hay,  late  cut  2.3            40.8  1.1  44.1 

Clover  hay,  average  quality         7.1             37.8  1.8  46.7 

Corn  silage,  average  quality           .9             12.6  .6  14.1 

Hominy  chops 6.7             613  7.6  75.6 

Wheat  bran 12.               39.8  2.7  54.5 

Linseed  meal 28.2            40.6  2.9  717 

The  second  step  is  to  calculate  the  pounds  of  digest- 
ible nutrients  in  the  quantities  of  the  several  feeding 
stuffs  to  be  used.  It  is  clear,  for  instance,  that  ten 
pounds  of  hay  will  contain  ten  one -hundredths  of  the 
amounts  in  one  hundred  pounds,  so  we  simply  need  to 
multiply  the  percentage  of  digestible  protein  and  so  on 
by  ten  and  divide  by  one  hundred  in  order  to  learn  what 
ten  pounds  of  hay  will  furnish  to  the  animal.  If  we  make 
this  computation  for  each  constituent  of  each  feeding 
stuff,  we  reach  the  figures  of  the  following  table 


288  The  Feeding  of  Animals 


Digestible 
protein 

lbs. 

Total 
Digestible                     digestible 

carbo-      Digestible    organic 
hydrates          fat            matter 
lbs.              lbs.             lbs. 

Nutritive 
ratio 

Timothy  hay,  10  lbs. 

.23 

4.08           .11           4.42 

Corn  silage,  25  lbs... 

.22 

3.15           .15           3.52 

Hominy  chops,  2  lbs. 

.13 

1.23           .15           1.51 

Wheat  bran,  3  lbs... 

.36 

1.19           .08           1.63 

.94  9.65  .49         11.08         1:11.5 

Several  authors  have  published  tables  showing  the 
amounts  of  digestible  nutrients  in  given  quantities  of 
our  feeding  stuffs,  which  still  further  shorten  the  work 
that  the  feeder  m-ust  do  in  computing  rations. 

When  we  come  to  compare  this  ration  with  the 
standard  ration  we  find  it  is  seriously  defective  in  two 
particulars;  it  contains  much  too  little  digestible  organic 
matter  and  the  nutritive  ratio  is  too  wide. 

In  order  to  correct  these  faults  -we  must  add  digesti- 
ble organic  matter  which  contains  a  much  larger  pro- 
portion of  protein  than  is  found  in  any  of  the  materials 
so  far  selected,  and  we  must  seek  such  a  supply  in  part 
at  least  among  the  highly  nitrogenous  feeding  stuffs  like 
the  oil  meals  and  gluten  meals.  It  is  easy  for  one  with 
experience  to  see  also  that  all  the  necessary  additional 
organic  matter  cannot  be  secured  from  a  highly  nitrog- 
enous food  without  increasing  the  protein  supply  un- 
necessarily. In  order  to  avoid  this,  the  amount  of 
silage  may  be  raised  ten  pounds  and  still  not  feed  an 
excessive  quantity.  If  clover  hay  is  available  it  would 
also  be  well  to  substitute  five  pounds  of  it  for  five 
pounds  of  the  timothy.  If,  then,  we  add  to  the  ration 
three  pounds  of  linseed  meal  we  shall  approximate  more 
nearly  to  our  standard. 


Calculation  of  Standard  Rations  289 

Total 
digestible 
Cartohy-  organic      Nutritive 

Protein      drates         Fat         matter  ratio 

lbs.  lbs.  lbs.  lbs. 

Timothy  hay,  5  lbs 11         2.04         .06         2.21 

Clover  hay,  5  lb«. 35         1.89         .09         2.33 

Corn  silage,  35  lbs 31         4.41         .21         4.93 

Hominy  chops,  2  lbs 13         1.23         .15         1.51 

Wheat  bran,  3  lbs 36         1.19         .08         1.63 

Linseed  meal,  N.  P.,  3  lbs..     .85        1.22         .09        2.16 

2.11       11.98         .68       14.77         1:6.4 

This  ratioii  is  still  below  the  standard  iu  quantity, 
but  as  the  relation  of  the  nutrients  is  approximately 
what  is  called  for,  it  is  only  necessary  to  increase  the 
quantities  of  each  component  about  one -fifteenth  in 
order  to  furnish  the  animal  sixteen  pounds  of  digestible 
organic  matter.  It  is,  however,  a  good  ration  for  cows 
of  the  smaller  breeds  weighing  from  800  to  900  pounds. 

There  are  several  points  to  be  considered  in  this 
connection.  First  of  all,  the  standard  rations  are  the 
quantities  to  be  fed  per  day  and  per  1,000  pounds  live 
weight.  This  is  ordinarily  taken  to  mean  that  if  a 
1,000 -pound  cow  requires  16  pounds  of  digestible 
nutrients  an  800 -pound  cow  should  be  supplied  with 
only  four-fifths  as  much,  or  12.8  pounds,  or  that 
a  1,200 -pound  horse  needs  50  per  cent  more  food 
than  one  weighing  800  pounds.  Unfortunately  this 
simple  mathematical  way  of  calculating  rations  does 
not  meet  the  plain  requirements  of  practice.  The  needs 
of  a  producing  or  working  animal  are  not  directly  pro- 
portional to  its  size,  although  it  is  more  nearly  so  with 
working  animals  than  with  those  fed  for  production. 
It  is  certain  that  an  exact  adjustment  of  a  ration  to  the 

s 


290  The  Feeding  of  Animals 

-weight  of  the  animal  would  produce  absurd  conditions, 
especially  in  the  case  of  cows  where  production  and  not 
the  size  of  the  animal  is  the  main  factor. 

However,  we  cannot  ignore  the  size  of  the  animal 
in  determining  the  quantity  of  the  ration.  Concern- 
ing this  Armsby  says:  "The  function  of  the  mainte- 
nance ration  is  essentially  to  supply  heat  to  the  body 
to  replace  the  constant  loss  that  takes  place.  Now, 
Henneberg  has  long  ago  shown  that,  in  round  num- 
bers, over  90  per  cent  of  this  heat  is  removed  by 
radiation  and  evaporation.  Consequently,  we  should 
expect  the  demands  of  the  organism  for  heat  (i.  e., 
for  maintenance),  to  be  proportional  to  its  surface 
(including  lung  surface),  rather  than  to  its  weight,  and 
the  more  recent  researches  of  Rubner  have  confirmed  this 
theoretical  conclusion."  For  the  purposes  of  calcula- 
tion it  is  assumed  that  animals  are  geometrically 
similar  figures  and  therefore  that  their  surfaces  are 
proportional  to  the  square  root  of  the  cube  of  their 
weights.  Several  steers  having  weights  from  1,0'JO 
pounds  up  to  1,700  pounds  would  need  on  this  basis 
amounts  of  digestible  food  for  maintenance  propor- 
tional to  figures  given  in  the  table  below  : 


Weight  of  the  animal 
approximately 

Proportion  of  food  per 
1,000  lbs.  live  weight 

1,000 

lbs. 

100 

1,100 

96 

1,200 

93 

1,300 

90 

1,400 

88 

1,500 

86 

1,G0() 

84 

1,700 

82 

The  Nutritive  Batio  291 

For  adjusting  a  maintenance  ration  to  the  weight  of 
a  steer  or  horse  this  method  seems  to  have  a  plausible 
basis,  but  it  is  evidently  less  applicable  to  dairy  cows 
or  rapidly  growing  or  fattening  animals,  for  in  these 
cases  size  is  not  so  largely  a  controlling  factor. 

Again,  is  there  a  fixed  quantity  and  proportion  of 
protein  from  which  it  is  unwise  to  deviate  ?  If  we 
are  trying  to  supply  the  needs  of  a  cow  giving  twenty - 
five  pounds  of  milk  or  of  a  steer  gain'ing  two  pounds 
of  body  substance  daily,  there  is  without  question  a 
minimum  quantity  of  food  protein  absolutely  neces- 
sary in  each  case,  but  what  these  minima  are  has  not 
yet  been  closely  determined.  These  necessary  quanti- 
ties are  undoubtedly  not  exactly  the  same  for  all 
individuals,  although  they  are  not  likely  to  differ 
widely  between  single  animals  of  the  same  class  and 
productive  capacity.  It  is  safe  to  assert  that  the  pro- 
tein standards  are  those  which  it  is  practicable  to 
feed  and  which  unquestionably  meet  the  demands  of 
intensive  production,  but  we  are  not  sure  thafe  when 
other  conditions  are  right  10  per  cent  more  or  10  per 
cent  less  than  the  specified  quantities  would  influence 
efficiency  either  waj^;  in  other  words,  we  have  no 
proof  in  those  cases  where  2.5  pounds  of  protein  is 
the  standard  for  a  milch  cow  that  2.75  pounds  would 
not  induce  larger  production  or  that  2.25  pounds 
would  not  meet  all  requirements  when  the  carbohy- 
drates are  present  in  sufficient  quantity. 

All  this  is  equivalent  to  saying  that  we  cannot  fix 
exact  nutritive  ratios.  There  is,  of  course,  a  min- 
imum food  energy  which  is  essential  for  sustaining  a 


292  The  Feeding  of  Animals 

particular  animal,  and  the  non- nitrogenous  nutrients 
should  be  present  in  sufficient  quantity  to  protect  the 
protein  that  it  may  be  applied  to  its  peculiar  uses 
rather  than  be  consumed  for  heat  production.  It 
is  more  than  probable,  though,  that  the  nutritive  ratio 
may  vary  considerably  from  the  German  standards 
without  causing  any  appreciable  influence  upon  growth, 
work  or  milk  yield. 

We  have  good  reasons  for  believing,  however,  that 
when  the  supply  of  food  meets  the  requirements  of 
the  animal  as  to  quantity,  the  nutritive  ratios 
given  in  the  feeding  standards  provide  fully  for  the 
needs  of  animals  under  all  conditions.  The  signifi- 
cant fact  is  that  in  practice  it  is  possible  to  depart 
so  widely  from  these  ratios  as  to  greatly  diminish  the 
efficiency  of  the  ration  for  specific  purposes,  and  this 
is  the  justification  of  standards  which  may  only  ap- 
proximate to  the  best,  but  which  serve  admirably  as 
a  guide  in  avoiding  serious  errors.  The  foregoing 
statements  do  not  mean  that  the  feeding  formulas  so 
far  published  are  the  result  of  guess-work  and  rest 
upon  no  basis  of  exact  observations,  for  this  is  not  true. 
It  is  simply  intended  to  point  out  the  fact  that  we  can- 
not now  set  exact  limits  to  the  formulas  of  nutrition. 

4.  The  rations  should  be  compounded  with  refer- 
ence to  the  quality  of  the  product.  Our  knowledge 
of  the  influence  of  foods  upon  the  quality  of  meat 
products  is  indefinite,  but  that  food  has  an  influence 
upon  the  flavor  of  milk  and  upon  the  chemical  and 
physical  properties  of  butter,  seems  to  be  fairly  well 
established. 


Business   Considerations  in   Selecting  Rations    293 

5.  Rations  should  be  compounded  with  reference  to 
the  home  supply  of  feeding  stuffs  and  to  market  prices. 
Economy  often  demands  that  the  materials  in  hand 
shall  be  used  even  if  the  ration  is  not  ideal.  Again, 
there  are  several  protein  foods  which  may  be  used, 
and  it  is  often  only  a  question  of  price  in  determin- 
ing which  should  be  purchased.  Notwithstanding  the 
claims  of  manufacturers,  there  is  no  one  feeding  stuff 
essential  to  the  health  of  animals  or  to  the  highest 
quality  of  the  product,  so  that  the  feeder  may  often 
consider  the  matter  of  cost  and  select  the  cheapest 
source  of  protein  without  in  any  way  impairing  the 
ration. 

Those  who  have  carefuUj'  followed  the  preceding 
statements  must  have  become  convinced  that  the  selec- 
tion of  a  ration  which  shall  be  the  best  possible  from 
a  business  standpoint  is  not  a  simple  matter.  We 
must  always  distinguish  between  the  combination  that 
is  most  efficient  physiologically  or  productively  and 
the  one  that  is  the  source  of  largest  i^rofit.  It  is  often 
the  case  —  perhaps  generally  —  that  a  food  mixture 
which  induces  a  high  rate  of  production  is  the  most 
profitable  one  to  use,  but  this  occurs  only  when 
business  conditions  make  it  possible.  Many  seem  to 
think  that  if  a  ration  is  "balanced"  it  necessarily  meets 
all  the  requirements  for  the  maximum  profit,  bnt  this 
is  an  erroneous  view. 

For  instance,  a  farmer  somewhat  remote  from  the 
markets  may  have  on  hand  an  abundant  supply  of 
hay  and  home -raised  grams  of  such  a  character  that 
it  is  impossible  to  compound  them  so  as  to  conform 


294  The  Feeding  of  Anhncds 

to  the  accepted  feeding  standard  for  milch  cows.  If 
the  prices  of  dairj^  products  are  low,  and  those  of  pro- 
tein feeding  stuffs  are  high,  it  is  entirely  possible  for 
the  farmer  to  secure  more  profit  from  his  cows  with 
an  "unbalanced"  ration  than  with  one  which  has  the 
standard  nutritive  ratio. 

The  western  stockman  can  generally  afford  to  waste 
corn  on  fattening  steers  rather  than  use  it  with  greater 
physiological  economy  by  mixing  it  with  purchased 
grains.  The  cost  of  the  latter  would  soon  offset  the 
profits  otherwise  possible.  All  this  is  equivalent  to 
saying  that  practical  considerations  often  justify  a 
wide  departure  from  the  standard  rations.  Hill  states 
the  case  well  when  he  says  : 

"The  study  of  the  requirements  of  the  individual 
animal  and  the  adapting  of  food  to  its  needs  is  to  be 
preferred  to  placing  the  herd,  as  a  whole,  upon  anj^ 
inflexible  ration.  The  capacity  of  an  animal  to  re- 
ceive, its  ability  to  produce,  the  effects  of  the  sundry 
feeds  upon  tlie  health  and  condition  of  the  animal, 
upon  its  appetite  and  taste,  upon  the  quality  of  the 
product,  the  money  values  of  feed  and  the  profits  to 
be  derived  from  their  use,  are  important  considera- 
tions which  do  not  enter  into  the  make-up  of  the 
physiological  standard,  but  which  are  vital  factors  in 
the  feeder's  problem.  Clearly  the  physiological  stand- 
ards may  supplement,  and  in  some  measure  guide,- 
judgment,  but  cannot  take  its  place." 


CHAPTER    XX 

MAINTENANCE  EATIONS 

A  MAINTENANCE  ratiou  is  one  supplying  the  needs 
of  an  animal  withont  production  of  any  kind  and  with 
no  loss  of  body  substance.  To  be  more  specific,  when 
an  ox  doing  no  work  excretes  just  the  quantities  of 
nitrogen  and  carbon  that  are  contained  in  the  food  con- 
sumed, he  is  said  to  be  eating  a  maintenance  ration. 
The  work  done  by  the  animal  at  rest  is  largely  needed 
in  the  following  directions:  the  chewing  of  food  and 
its  movement  along  the  intestinal  tract;  the  muscular 
action  of  the  heart  in  causing  blood  circulation,  and  the 
metabolic  activity  of  the  cells  in  causing  the  chemical 
transformation  of  the  nutrients.  Some  work  is  also 
done  in  moving  the  body.  The  demands  upon  the  food 
for  maintenance  purposes  are  therefore  entirely  for  the 
production  of  muscular  energy  and  heat. 

Nine -tenths  or  more  of  a  maintenance  ration  may 
consist  of  carbohydrates  which,  because  the  income  and 
outgo  are  balanced,  are  used  solely  as  fuel.  Only  a  very 
small  amount  of  protein  is  necessarily  destroyed  by  a 
resting  animal,  although  a  minimum  food  supply  is 
absolutely  essential  if  the  nitrogenous  tissues  of  the 
body  are  to  be  kept  from  wasting.  If  an  animal  is 
not   eating   protein,   urea   will   continue   to    appear   in 

(295) 


296  The  Feeding  of  Animals 

the  urine  and  in  time  protein  starvation  will  cause 
death. 

Any  ration  fed  for  production  may  be  looked  upon 
as  made  up  of  two  parts,  that  which  is  needed  to  main- 
tain the  animal  and  that  which  may  be  applied  to 
growth  or  the  formation  of  milk  solids.  It  is  possible, 
of  course,  for  the  production  of  milk  or  wool  to  occur 
when  the  cow  or  sheep  is  fed  what  is  really  only  a 
maintenance  ration,  but  the  materials  for  production 
under  these  circumstances  are  furnished  at  the  expense 
of  the  body  substance.  With  what  is  regarded  as  liberal 
feeding,  from  one -third  to  one -half  of  a  production 
ration  is  needed  for  maintenance  purposes.  It  seems 
fitting,  then,  to  speak  of  a  maintenance  ration  as  a  fun- 
damental quantity,  a  knowledge  of  which  is  important 
to  both  science  and  practice.  It  is  clear  that  no  rational 
understanding  of  the  uses  of  food  can  be  had  unless  we 
know  what  amount  is  required  simply  for  maintenance, 
and  the  feeder  is  certainly  helped  to  a  more  intelligent 
compounding  of  rations  if  he  has  some  means  of  judg- 
ing how  large  an  excess  he  is  supplying  for  production 
purposes.  Occasionally,  too,  it  is  desired  to  provide 
horses  and  other  animals  when  not  at  work  with  just 
enough  food  to  keep  them  in  a  uniform  condition  with- 
out gain  or  loss. 

No  ration  is  more  easily  provided  from  the  ordinary 
farm  supply  than  is  that  for  maintenance,  for  two 
reasons:  (1)  because  the  quantity  of  available  nutrients 
which  must  be  eaten  is  so  small  that  this  ration  may 
be  wholly  or  mostly  made  up  of  bulky  materials  such 
as  corn  fodder  and  hay;    (2)  because  investigation  has 


Maintamcmce  Bequirements  of  Bovines  297 

demonstrated  that  mere  maintenance  demands  a  com- 
paratively small  amount  of  protein  and  so  this  ration 
may  have  a  wide  nutritive  ratio  such  as  pertains  to  the 
nutrients  of  the  more  common  farm  products. 

MAINTENANCE  FOOD  FOR  BOVINES 

Experiments  having  for  their  object  a  determination 
of  the  daily  quantity  of  nutrients  necessary  to  simply 
maintain  animals  of  this  class  were  conducted  by  Hen- 
neberg  and  Stohman  with  oxen  as  long  ago  as  1858.  A 
number  of  rations  were  fed  and  the  conclusions  which 
were  reached  were  based  upon  the  amount  of  food 
digested,  the  gain  or  loss  of  nitrogenous  tissue  by  the 
animals  and  their  weights  and  general  appearance.  The 
average  daily  quantities  of  digestible  nutrients  which 
appeared  to  be  sufficient  to  maintain  a  1,000 -pound  ox 
without  growth  or  loss  was  approximately. 8. 2  pounds, 
of  which  .53  pound  was  protein,  the  whole  having  an 
energy  or  heat  value  of  not  far  from  15,000  Calories. 
Because  of  the  high  temperature  of  the  stalls  used  in 
the  above-named  experiments,  Wolff  estimated  later 
that  for  winter  feeding  the  standard  should  be  8.9 
pounds  of  digestible  nutrients,  of  which  .7  pound 
should  be  protein,  the  energy  value  being  approximately 
16,000  Calories,  and  even  until  now  Wolff's  figures  are 
published  as  the  standard  maintenance  ration. 

It  is  certainly  time  that  this  standard  should  be 
revised.  The  earlier  experiments  on  which  it  was 
based  furnished  data  insufficient  for  accurate  con- 
clusions, for   the  only  means  of   judging  whether  the 


298  The  Feeding  of  Animals 

animals  were  gaining  or  losing  bodj'  substance  were 
the  changes  in  live  weight,  which  cannot  be  regarded 
as  conclusive  evidence.  Some  of  the  earlier  feeding 
experiments  conducted  in  the  United  States,  especially 
those  of  Sanborn  and  Caldwell,  indicated  that  a  ra- 
tion based  on  Wolff's  standard  was  capable  of  caus- 
ing a  material  growth  of  steers,  and  the  accuracy  of 
Wolff's  figures  was  called  into  question.  Later  obser- 
vations of  a  more  exact  character  have  shown  quite 
conclusively  that  a  1,000-pound  steer  may  be  main- 
tained without  loss  of  body  substances  on  considerably 
less  than  8.9  pounds,  or  even  8  pounds,  of  digestible 
nutrients  per  day. 

Elaborate  experiments  by  Kiihn  from  the  j^ears 
1882  to  1890,  afterwards  discussed  by  Kellner,  were 
regarded  by  the  latter  as  justifying  the  conclusion 
that  the  minimum  quantity  of  digestible  organic  mat- 
ter which  will  maintain  a  1,000 -pound  mature  ox  at 
rest  is  7.3  pounds,  .7  of  a  pound  of  which  should  be 
protein.  Later  Armsby,  in  presenting  the  results  of 
experiments  of  his  own  in  connection  with  a  critical 
review  of  Kiihn 's  work,  concludes  that  "we  maj^  place 
the  average  maintenance  of  a  steer  weighing  500  kgs. 
(1,100  pounds)  and  receiving  only  a  mainly  coarse 
fodder  at  13,000  Calories  of  available  energy."  As 
Armsby  found  one  gram  of  digestible  matter  from 
timothy  hay  to  be  equal  to  3.62  Calories  of  available- 
energy,  13,000  Calories  would  equal  7.92  pounds  of 
digestible  matter  from  this  source.  This  would  be 
the  same  as  7.4  pounds  for  a  1,000-pound  animal. 
(See  method  of  calculation  in  Chapter  XIX.) 


Maintenance  Rations  299 

Still  later,  Kellner,  basing  his  figures  upon  extensive 
researches  by  himself  and  associates,  which  are  the  most 
elaborate  so  far  made,  gives  us  the  following  as  the 
minimum  quantities  wliich  will  satisfy  the  maintenance 
needs  of  mature  animals  of  different  weights: 


Approxim.-ite  weight 
of  animal 

Energy 
Cal. 

Digestible 

organic  substance  from 

average  meadow  hay 

lbs. 

lbs. 

1,000 

10,740 

6.75 

1,100 

11,520 

7.22 

1,200 

12,280 

7.72 

1,300 

13,010 

8.18 

1,400 

13,720 

8.62 

1,500 

14,420 

9.06 

The  necessary  quantity  of  available  nutrients  may 
be  larger  if  only  verj'  ripe,  coarse  food  is  fed,  than  if 
the  ration  is  part  grain,  because  of  the  somewhat  less 
available  energy  from  the  digested  part  of  the  former. 
In  order  to  express  a  maintenance  ration  for  bovines 
in  terms  of  hay  and  grain,  there  are  given  in  this  con- 
nection several  mixtures,  which,  on  the  basis  of  aver- 
age composition  and  digestibility,  will  furnish  quite 
closely  the  necessary  digestible  matter,  using  Armsby's 
conclusions  as  the  basis  for  calculation  : 


f  12  lb 
I    3  lb 


To  maintain  a  1,000 -pound  animal 

L2  l]>s.  average  timothy  hay.  (  23  lbs.  mature  corn  silage. 

bs.  wheat  bran.  '6  \    5  lbs.  timothy  hay. 

i    3  lbs.  wheat  bran, 
r  8  lbs.  corn  stover.  (  5  lbs.  timothy  hay. 

2^6  lbs.  clover  hay.  4^5  lbs.  clover  hay. 

(  3  lbs.  corn  and  cob  meal.  '-  4  lbs.  corn  and  cob  meal. 

5.     15%  lbs.  good  mixed  hay. 


300  The  Feeding  of  Anhnals 

These  combinations  are  merely  illustrative.  Many  others 
furnishing  an  equivalent  quantity  of  available  nutri- 
ents may  be  used.  Doubtless  these  various  mixtures 
will  not  show  equal  efficiency.  'Ration  No.  3  would 
probably  be  more  satisfactory  than  No.  5,  because  of 
greater  palatableness.  All  such  facts  as  the  proportion 
of  grain  in  the  mixture,  the  stage  of  growth  of  the 
fodder,  whether  early  or  late  cut,  immature  or  mature, 
the  amount  of  moisture  present,  as  in  stover,  and  the 
completeness  of  preservation,  will  have  an  influence 
upon  the  nutritive  effect  of  a  ration,  and  these  factors 
must  be  considered  according  to  the  best  judgment  of 
the  feeder.  It  is  possible,  without  question,  to  main- 
tain an  animal  on  one  fodder  alone,  such  as  hay,  bnt 
for  several  obvious  reasons  it  is  better  to  feed  a  mix- 
ture. 

The  maintenance  rations  heretofore  stated  apply  to 
a  1,000 -pound  animal.  For  animals  weighing  more 
or  less  the  quantity  should  be  increased  or  diminished, 
but  not  in  just  the  ratio  in  which  the  animal  varies  in 
weight.  For  information  on  this  point  the  reader 
should  refer  to  what  is  given  in  the  chapter  on  com- 
pounding rations. 

MAINTENANCE     FOOD    FOR    HORSES 

The  general  facts  which  have  been  presented  in  re.- 
lation  to  the  function  and  character  of  a  maintenance 
ration   are  as   applicable  to   horses  as  to  bovines.      It 
is   true,    however,    that    rations    simply   sufficient    for 
maintenance   purposes  have   a  very  limited  application 


Maintenance  Requirements  of  Horses  301 

with  horses,  because  iu  nearly  all  cases  they  are  at 
least  used  for  occasional  driving  or  light  work,  and 
even  if  merely  "boarded,"  regular  exercise  is  necessary 
to  their  welfare. 

If  recent  conclusions  are  sound,  a  horse  needs 
somewhat  less  digestible  food  for  mere  maintenance 
than  a  steer  of  equal  weight.  Zuntz,  who  has  so 
thoroughly  studied  the  nutrition  of  the  horse,  con- 
cludes, after  a  critical  survey  of  the  results  of  other 
men  in  connection  with  the  elaborate  data  from  his 
own  extended  investigations,  that  a  1,000 -pound  horse 
can  be  maintained  on  6.4  pounds  of  nutrients,  pro- 
vided the  total  ration  contains  not  more  than  three 
pounds  of  crude  fiber.  This  means  that  the  nutrients 
should  come  from  a  mixture  of  hay  and  grain  if  this 
minimum  quantity  is  to  be  sufficient.  Were  only  hay 
to  be  fed  the  necessary  nutrients  would  probably  ex- 
ceed the  amount  named. 

Grandeau  in  his  experiments  found  that  three  horses, 
whose  mean  weight  was  852  pounds,  were  maintained 
for  fourteen  months  on  17.6  pounds  of  hay  per  day, 
from  which  the  three  animals  digested  an  average  of 
6.06  pounds  of  organic  matter.  Using  the  method  of 
computation  already  described,  this  is  equal  to  6.75 
pounds  of  digestible  nutrients  for  a  1,000 -pound 
horse,  a  result  not  greatly  different  from  that  of 
Zuntz. 

The  latest  conclusion  of  Wolff  was  that  a  1,100- 
pound  horse  should  have  for  maintenance  at  rest  7.26 
pounds  of  digestible  organic  matter  daily,  exclusive  of 
the  digest-ed  crude  fiber,  which  would  be  the  same  a« 


302  The  Feeding  of  Animals 

6.78  pounds  of  fiber-free  nutrients  for  a  1,000 -pound 
horse.  As  Wolff  regarded  the  fiber  as  useless  to  a 
horse,  either  for  maintenance  or  for  production  of 
work,  the  last  figures  represent  his  estimate  of  the 
maintenance  needs  of  a  horse  at  rest. 

It  is  proper  to  remark  that  Wolff's  views  as  to  the 
nutritive  value  of  crude  fiber  are  not  generally  accepted. 

In  calculating  rations  for  horses,  the  coefficient  of 
digestibility  obtained  in  experiments  with  this  class  of 
animals  should  be  used,  coarse  fodders,  as  stated 
previously,  not  being  so  efficiently  digested  by  horses 
as  by  bo  vines  or  sheep.  For  this  reason,  the  gross 
weight  of  the  maintenance  food  for  horses  maj'  be  as 
great  as  that  for  ruminants,  though  the  actual  nu- 
trients needed  are  less.  Accepting  6.G  pounds  of 
digestible  organic  matter  as  the  daily  requirements  of  a 
resting  horse,  the  following  rations  would  maintain  a 
1,000- pound  animal  for  one  day: 

I  16X  lbs.  medium  quality  {    ^^  ^^^-  ^^^^^  ^^J- 

\  mixed  hay.  j  3^  lbs.  bran,  or 

I      3  lbs.  oats,  or 

2  I  10  lbs.  timothy  hay.  [  2%  lbs.  cracked  corn. 

''Is  lbs.  oats. 


r  10  lbs. 

timothy. 

10  lbs.  timothy  hay. 
4  lbs.  cracked  corn. 

q\    10  lbs. 
(  2%  lbs. 

carrots, 
corn. 

r  10  lbs. 

mixed  hay 

10  lbs.  medium  mixed  liay. 

7  ]    10  lbs. 

carrots. 

4%  lbs.  wheat  bran. 

(  2%  lbs. 

oats. 

r    10  lbs. 

mixed  hay. 

8  \      S  lbs. 

carrots. 

I  3X  lbs. 

bran, 

Maintenance  Rations  303 

These  rations  serve  as  examples  and  also  indicate 
how  with  ten  pounds  or  twelve  pounds  of  hay  the  sev- 
eral grains  mentioned  may  be  combined  to  give  a  main- 
tenance ration.  It  is  not  wise  to  feed  a  horse  on  hay 
alone,  even  when  doing  no  work.  Ten  to  twelve  pounds 
of  hay  are  enough  coarse  fodder,  which  may  be  supple- 
mented to  advantage  by  both  roots  and  grain. 


CHAPTER  XXI 

MILE  PRODUCTION 

Milk,  like  all  other  animal  products,  is  derived  from 
the  food.  Its  secretion  stands  almost  unrivaled  as  an 
example  of  the  rapid,  extensive  and  continuous  trans- 
formation of  the  food  into  animal  compounds.  In  no 
other  instance,  except  perhaps  in  the  case  of  the  earliest 
growth  of  animals,  is  so  large  a  proportion  of  the 
digested  nutrients  utilized  in  building  new  material  or 
is  there  so  intimate  a  relation  between  the  extent  and 
kind  of  the  feeding  and  the  extent  and  character  of  the 
resulting  product.  For  these  and  other  reasons,  the 
successful  feeding  of  milch  cows  requires,  perhaps, 
greater  expertness  and  a  wider  knowledge  of  facts  than 
any  other  department  of  animal  husbandry.  This  will 
appear  more  fully  as  we  continue  to  develop  this  subject. 

It  is  not  proposed  in  this  connection  to  enter  into 
an  elaborate  discussion  of  the  chemistry  and  secretion 
of  milk,  for  this  is  presented  elsewhere  in  the  series 
of  which  this  volume  is  a  part.  It  is  essential  to 
present  purposes,  however,  that  we  call  to  mind  certain 
facts  which  are  pertinent  to  a  consideration  of  the  food 
relations  of  milk  formation. 

Milk  is  a  fluid  that  is  secreted  by  all  mammals  in  a 
gland  which  with  the  cow  is  called  the  udder.     It  cou- 

(304) 


Composition  of  Milk  305 

tains  water  and  solids,  the  latter  being  made  np  of 
mineral  compounds,  proteids,  fats  and  sugar.  The 
average  composition  of  normal  cow's  milk,  excluding 
samples  of  unusual  character,  according  to  a  compila- 
tion by  Van  Slyke  of  5,552  American  analyses  is  as 
follows: 

Total  solids  Ash  Proteids  Fats  Sugar  Water 


%  %  %  % 


rt 


12.9  .7  3.2  3.9  5.1  87.1 

The  variations  in  the  composition  of  cows'  milk  are 
large,  the  proportion  of  water  ranging  under  per- 
fectly- normal  conditions  from  84  to  89  per  cent,  with 
occasional  analyses  entirely  outside  these  limits. 
The  chief  known  causes  of  such  variations  are  breed, 
individuality,  period  of  lactation,  and  nervous  dis- 
turbances. There  are  material  daily  fluctuations  as 
well,  for  which  no  reasons  can  now  be  assigned. 
These  changes  are  mostly  in  the  proportions  of  water 
and  total  solids,  for  the  composition  of  the  solids,  that 
is,  the  relative  proportion  of  proteids,  butter  fats  and 
sugar,  is  remarkably  constant  in  the  same  animal.  The 
effect  of  breed  in  cows  is  illustrated  by  averages  ob- 
tained  in  breed  tests  at  three  experiment  stations: 

Holstein       Ayrshire       Jersey 

%  %  % 

Total  solids 12.2  12.9  15. 

Fat 3.4  3.6  5.3 

Solids  not  fat 8.8  9.3  9.7 

These  variations  and  those  due  to  other  causes  are 
important   in  considering  the  relation  of  milk  forma- 

T 


306  The  Feeding  of  Animals 

tion  to  nutrition,  because  the  food  expense  of  milk  is 
determined,  other  things  being  equal,  not  by  the  vol- 
ume but  by  the  milk  solids  elaborated,  for  which 
reason  the  draft  upon  the  supply  of  nutrients,  water 
excepted,  is  greater  for  the  secretion  of  100  quarts 
of  Jersey  milk  than  for  the  same  quantity  of  Holstein 
milk.  In  studying  the  economy  of  milk  production, 
therefore,  we  should  consider  the  relation  of  food  to 
milk  solids  and  not  to  milk  volume. 

MILK     SECRETION 

There  is  no  milk  in  an  animal's  food,  that 'is  to 
say,  hay  and  grain  contain  no  casein,  butter  fat  or 
milk  sugar.  They  do  contain  nutrients,  which,  when 
subjected  to  the  vital  processes  of  the  animal,  are 
ultimately  transformed  into  the  constituents  of  milk. 
The  mammary  gland  is  not  a  sieve  through  which  cer- 
tain compounds  in  the  blood  are  strained  into  the  udder 
cavities,  but  it  is  a  specialized  tissue  in  which  wonder- 
ful and  extensive  chemical  changes  occur.  Here,  for 
the  first  time,  we  find  casein,  the  mixture  of  compounds 
known  as  butter  fat,  and  a  sugar  unlike  any  that  is 
found  in  plants,  or  in  any  other  part  of  the  animal 
organism.  Vegetable  fats  contain  glycerides  similar  to 
some  of  those  found  in  milk,  to  be  sure,  but  not  in 
the  same  number  or  proportions.  One  fact,  moreover,, 
which  dairymen  have  been  slow  to  recognize  in  all  its 
significance,  is  that  the  udder  of  each  individual  cow 
is  a  law  unto  itself  in  the  characteristics  of  the  milk 
which  it  secretes,  and  is  not  subject   in  any  large  de- 


Origin  of  MilJc  Solids  307 

gree  to  control  through  feeding*  or  other  treatment 
that  is  not  actual    abuse. 

The  manner  of  milk  secretion  is  something  of  which 
we  know  but  little,  and  this  is,  perhaps,  not  immedi- 
ately important  to  the  dairyman.  The  food  source  of 
the  constituents  of  milk  is,  on  the  other  hand,  a  mat- 
ter of  great  practical  interest,  and  here  we  have  infor- 
mation more  or  less  definite. 

Sources  of  milli  solids. —  The  previous  discussion  of 
the  functions  of  nutrients  must  have  made  it  clear  that 
the  proteids  of  the  milk  can  have  only  one  source; 
viz.,  the  proteids  of  the  food,  a  unanimous  conclusion 
which  rests  upon  experimental  evidence  as  well  as 
upon  the  universally  accepted  truth  that  the  animal 
organism  does  not  have  the  power  to  construct  pro- 
teids from  simpler  compounds.  It  now  seems  quite 
certain  that  the  proteids  are  the  only  constituents  of 
milk  which  must  have  their  origin  exclusively  in  the 
food  proteids,  for  we  have  apparently  sound  reasons 
for  believing  that  milk  sugar  and  butter  fat  are  con- 
structed, in  part  at  least,  from  carbohydrates.  In  an 
investigation  at  the  New  York  Agricultural  Experiment 
Station  as  to  the  food  sources  of  milk  fat,  two  cows, 
both  of  which  gained  materially  in  live  weight  during 
experiments  continuing  two  months  or  over,  produced 
respectively  nineteen  pounds  and  forty  pounds  more  of 
butter -fat  than  could  be  accounted  for  from  the  food 
fat  and  available  proteids.  The  amount  of  digestible 
food  fat  supplied  was  relatively  insignificant  and  the 
secretion  of  milk  fat  seemed  to  be  related  in  no  direct 
way  to  the  protein  exchange.     These  observations  led 


308  The  Feeding  of  Animals 

straight  to  the  couchisioii  that  carbohydrates  are  milk 
fat  formers.  The  extent  to  which  food  fat  assists 
in  the  production  of  milk  fat  is  not  yet  determined. 
It  cannot  be  safely  asserted  that  the  ingested  fats  do 
not  pass  directly  into  the  milk,  but  it  seems  quite 
evident  that  the  larger  part  of  the  gl^'cerides  of  milk 
have  their  origin  in  the  animal.  We  are  not  sure, 
either,  whether  protein  is  ever  a  source  of  milk  fat, 
but  that  it  is  a  necessary  source  now  seems  quite  im- 
probable. 

The  rate  of  formation  of  milk  solids. — A  cow  yield- 
ing 6,000  pounds  of  average  milk  per  year  is  not  re- 
garded as  an  unusual  animal.  This  means,  however, 
the  annual  production  of  not  less  than  780  pounds  of 
milk -solids,  an  amount  at  least  double  the  dry  matter 
in  the  body  of  a  cow  weighing  900  pounds.  When 
we  consider  that  this  manufacture  of  new  material  is 
carried  on  not  only  during  a  single  year,  but  through 
the  entire  adult  life  of  the  animal,  we  begin  to  realize 
how  extensive  are  the  demands  upon  the  food  supply. 
Still  more  striking  is  the  case  of  high  grade  cows 
yielding  annually  over  half  a  ton  of  milk  solids,  and 
when  we  remember  the  performance  of  Clothilde,  whose 
26,000  pounds  of  milk  produced  in  one  year  certainly 
contained  more  than  2,500  pounds  of  solid  matter,  we 
must  regard  the  cow  as  possessing  w^onderful  powers 
of  transmutation.  Her  capacity  for  the  rapid  and  eco- 
nomical production  of  human  food  of  the  highest  quality 
is  not  equaled  by  an  other  animal. 

No  facts  could  more  forcibly  illustrate  the  necessity 
of  liberal  and  proper  rations  for  the  milch  cow. 


Food  Requirements  for  Milk  Production         309 

THE  AMOUNT  AND  CHARACTER  OF  THE  RATION  FOR 
MILK  PRODUCTION 

This  ration  is  used  iu  various  directions.  It  must 
supply  the  raw  materials  for  milk  formation,  provide 
for  the  growth  of  the  foetus,  sustain  the  effort  of 
milk  secretion  and  maintain  the  usual  and  necessarj- 
functions  of  the  animal  body.  The  nature  and  extent 
of  these  uses  are  in  part  quite  definitely  understood. 
First  of  all,  the  kind  and  quantity  of  milk  solids  may 
be  estimated  for  any  given  case.  The  daily  production 
of  thirty  pounds  of  average  milk,  a  performance  rea- 
sonably to  be  expected  in  a  good  herd,  involves  the 
elaboration  of  3.87  pounds  of  milk  solids.  For  mere 
maintenance  it  is  fair  to  assume  that  the  food  require- 
ments of  the  cow  and  steer  would  not  be  greatly  un- 
like, disregarding  the  demand  for  energy  utilized  in 
milk  secretion,  and  for  the  material  used  in  the  growth 
of  the  young.  On  this  basis  the  milk  solids  and  the 
mere  maintenance  of  the  cow  call  for  about  11.25 
pounds  of  dry  matter  daily,  a  quantity  utterly  insuffi- 
cient, as  experience  teaches,  to  maintain  a  cow  giving 
thirty  pounds  of  average  milk.  We  are  led  to  the 
reasonable  conclusion  that  outside  the  building  of  milk 
solids,  a  large  expenditure  of  food  energy  is  required 
to  sustain  the  nerve  force,  metabolic  cell  activity  and 
warming  of  the  extra  water  and  food,  which  are  neces- 
sarily involved  in  milk  secretion.  This  view  is  sus- 
tained by  the  results  of  investigation.  In  unpublished 
experiments  by  the  writer  with  two  cows  in  full  flow 
of  milk,  which  made  only  a  slight  gain  in  body  weight, 


310  The  Feeding  of  Animals 

the  available  energy  of  the  rations  and  of  the  milk  was 
determined.  The  figures  reached  were  approximate!}^ 
as  follows  : 

Cow  10  Cow  12 

wt.  775  lbs.  wt.  1,200  lbs. 

Cal.  Cal. 

Available  energy  of  ration    27,120  31,300 

Energy  of  milk  solids 8,450  10,200 

Energy  not  used  in  milk 18,670  21,100 

Maintenance  needs  of  resting  animal. ..     10,100  13,700 

Balance  of  energy  not  accounted  for  .. .       8,570  7,400 

This  energy  not  accounted  for,  amounting  with  the 
two  cows  to  more  than  one -fourth  the  total  available 
energy  of  the  rations,  may  properly  be  charged  to  the 
work  of  milk  formation.  Science  and  practice  agree 
in  naming  15.5  to  16.5  pounds  of  digestible  organic 
matter  as  approximately  the  proper  daily  amount  of 
digestible  nutrients  for  economical  milk  production 
with  a  good  cow  of  average  size,  much  less  than  which 
is  not  to  be  considered  as  generous  feeding.  The  nec- 
essary supply  of  nutrients  will  vary  somewhat  accord- 
ing to  the  size  of  the  cow,  but  the  gradation  of 
quantity  should  by  no  means  be  directly  proportional 
to  live  weight.  Productivity  independent  of  size  is  a 
controlling  factor.  In  general  small  cows  eat  propor- 
tionately more  food  than  larger  ones. 

The  question  now  arises,  What  proportion  of  this 
quantity  should  be  protein  ?  The  actual  amount  of 
proteids  in  our  thirty  pounds  of  average  milk  is  about 
one  pound.  If  .60  pound  is  needed  daily  for  mere 
maintenance  as  in  the  case  of  the  steer,  we  can  see 
where  1.6  pounds  of  protein  must  be  used,  a  quantity 


Food  Requirements  for  Milk   Production         311 

which  is  now  regarded  as  too  small  when  both  food 
ecouomj-  and  the  efficiency  of  the  ration  are  considered. 
With  this  amount  of  protein  in  sixteen  pounds  of  total 
digestible  matter,  the  nutritive  ratio  of  the  ration  would 
be  about  1:9.5.  A  ration  with  as  wide  a  ratio  as  this 
is  regarded  by  the  great  majority  of  careful  experi- 
menters, and  most  intelligent  dairymen,  as  less  efficient 
than  one  richer  in  protein.  While  it  is  not  possible 
to  point  out  just  how  more  protein  is  used,  there  is  no 
question  but  that  a  larger  quantity  promotes  the  flow 
of  milk.  Few  instances  are  on  record  where,  in  care- 
fully conducted  experiment  station  work,  other  condi- 
tions being  the  same,  a  moderate  ration  with  a  nutritive 
ratio  of  1:5.5  to  1:6.5  has  not  proved  to  be  more 
efficient  than  one  equivalent  in  quantity  but  with  a 
ratio  materially  wider.  The  observations  of  Atwater 
and  Woods  among  the  dair\'  herds  of  Connecticut, 
where  the  owners  were  induced  to  narrow  the  rations 
they  were  found  to  be  using,  gave  emphatic  testimony 
as  to  the  desirability  of  a  larger  proportion  of  protein 
than  is  ordinarily  supplied  in  a  home-grown  ration. 
This  added  protein  may  not  be  needed  for  construction 
uses,  but  its  presence  certainly  in  some  way  induces 
an  increased  milk  secretion.  The  chemical  changes 
involved  in  milk  formation  are  obscure  and  complex, 
and  it  may  be  that  this  extra  protein  somehow  enters 
into  these  transformations.  One  view  which  appears 
to  be  rational  is  that  the  presence  of  a  generous  amount 
of  circulatory  protein  stimulates  the  cells  of  the  body 
to  great  metabolic  activity,  thus  promoting  the  secretion 
of  milk  solids. 


312  -    The  Feeding  of  Animals 

According  to  the  majority  of  testimony  available,  a 
cow  of  average  size  and  good  capacity  should  receive 
at  least  2.25  pounds  of  protein  daily  during  the  full 
flow  of  milk,  the  ration  to  have  a  nutritive  ratio  not 
wider  than  1:G.5.  The  nutritive  ratio  of  j^oung  pasture 
grass,  perhaps  as  efficient  a  milk -producing  food  as  we 
have,  is  even  narrower  than  this,  a  fact  which  doubt- 
less explains  in  part  the  large  flow  of  milk  from 
abundant  June  pasturage,  and  which  offers  a  sugges- 
tion for  the  compounding  of  winter  rations. 

While  the  importance  of  nitrogenous  feeding  stuffs 
to  a  dairy  herd  is  conceded,  there  is  a  tendencj^  with 
certain  writers  to  distort  the  relation  of  protein  to 
milk  production.  Their  utterances  give  the  impres- 
sion that  in  feeding  milch  cows  protein  is  about  the 
only  factor  to  be  considered.  This  view  is  typified  by 
the  assertion  that  "a  cow  gives  milk  only  in  propor- 
tion to  the  protein  that  she  receives,"  a  remark  which 
might  be  made  with  equal  accuracy  about  carbohy- 
drates. It  is  true  that  even  if  carbohydrates  are  sup- 
plied in  abundance,  a  depression  of  the  protein  below 
a  certain  limit  will  diminish  the  milk  flow.  It  is  also 
true  that  when  sufficient  protein  is  fed,  a  reduction  of 
the  carbohydrates  below  the  necessary  quantity  w411 
cut  down  the  milk  yield.  An  adequate  supply  of  easilj' 
digestible  carbohydrates  is  no  less  important  physio- 
logically than  keeping  up  the  necessary  proportion  of 
protein,  though  the  former  may  be  accomplished  more 
easily  than  the  latter  because  of  the  usual  character 
of  home -raised  crops. 

The  following  are  illustrative  examples  of  well-corn- 


Good  MilJc  Rations  313 

pounded  rations  for  cows  of  moderate  size  and  fairly 
large  productive  capacity  : 


f    10  lbs.  clover  hay. 
35  lbs.  corn  silage. 
2  lbs.  hominy  chops. 
4X  lbs.  wheat  bran. 
.  2X  lbs.  linseed  meal,  N.  P 

6  lbs.  clover  hay. 
10  lbs.  mixed  meadow  hay 
25  lbs.  mangels. 


10  lbs.  mixed  meadow  hay. 
40  lbs.  corn  silage. 

4  lbs.  wheat  middlings. 
3  lbs,  malt  sprouts. 

1  lb.  gluten  meal. 

10  lbs.  corn  stover. 

5  lbs.  alfalfa  hay. 
25  lbs.  sugar  beets. 


3  lbs.  corn  meal.  j      3  lbs.  corn  and  cob  meal. 
2  lbs.  wheat  bran.  3  lbs.  buckw't  middlings. 

2  lbs.  brewer's  grain.  I.ji/  jy^^    cottonseed  meal. 
2  lbs.  gluten  meal. 

If  12  lbs.  clover  or  alfalfa  hay. 
30  lbs.  corn  silage. 
4  lbs.  ground  oats. 
I    3  lbs.  ground  peas. 
[    2  lbs.  brewer's  grains. 

These  rations  may  be  criticised  on  the  ground  that 
they  are  too  small  to  sustain  heavy  milk  production. 
This  would  be  a  just  criticism  for  cows  of  large  ca- 
pacity that  are  furnishing  high-priced  milk. 

It  is  the  writer's  opinion  that  under  ordinary  con- 
ditions few  cows  under  1,000  pounds  in  weight  will 
render  larger  profit  from  heavier  rations. 

The  sources  of  protein  for  milk  production. — The 
dairyman  has  constantly  to  face  the  fact  that  from  the 
usual  list  of  home-grown  feeding  stuffs  it  is  difficult 
to  make  up  a  ration  throughout  an  entire  season  with 
a  nutritive  ratio  much  narrower  than  1:8,  and  a  propor- 
tion of  protein  even  as   high  as  this  requires  a  gener- 


314  The  Feeding  of  Animals 

ous  admixture  of  clover  in  the  hay,  and  the  use  of 
more  or  less  oats  or  peas  in  the  grain  ration.  It 
should  not  be  forgotten  that  the  plants  used  for  for- 
age crops  are  generally  not  harvested  until  they  are 
approaching  maturity,  and  as  the  later  growth  of 
most  plants  is  largely  due  to  the  formation  of  non- 
nitrogenous  compounds,  the  hay  and  other  fodders 
stored  for  winter  feeding  are  comparatively  poor  in 
nitrogen  compounds.  On  those  farms  where  the  hay 
crop,  comes  largely  from  the  true  grasses,  like  timothy 
and  red -top,  and  where  the  corn  crop  is  a  prominent 
feature,  a  home-raised  milk  ration  having  a  maximum 
efficiency  per  unit-  of  dry  matter  consumed  is  not  pos- 
sible. On  the  other  hand,  where  alfalfa  and  clovers 
constitute  a  good  proportion  of  the  hay,  and  where 
generous  areas  of  peas  and  oats  are  grown,  a  ration 
compounded  from  home  resources  may  have  a  high 
milk  -  producing  efficiency. 

It  must  be  confessed,  however,  that  most  dairy  farms 
are  lacking  in  a  proper  home-raised  supply  of  the  more 
nitrogenous  feeding  stuffs,  and  as  nearly  all  dairymen 
depend  to  some  extent  upon  purchased  grain,  it  is  a 
quite  prevalent  custom  for  them  to  seek  those  by-prod- 
ucts 'that  will  strengthen  the  protein  side  of  the 
ration,  a  course  which  they  have  been  led  to  adopt 
through  the  teachings  of  science.  It  is  unquestionablj^ 
true  that  farmers  should  be  more  independent  of  the 
markets,  and  they  certainly  may  be  if  an  intensive 
system  of  cultivating  well -selected  crops  is  adopted  ; 
but  so  long  as  more  or  less  grain  will  certainly  be 
purchased,  it  is  wise  to  consider  the  matter  of  select- 


Sources  of  Purchased  Protein  315 

ing  commercial  protein  feeds  for  dairy  cows.  Those 
from  which  it  is  possible  to  choose  are  the  oil  meals, 
the  gluten  meals  and  feeds,  brewers'  grains,  malt 
sprouts,  peas  and  buckwheat  middlings.  The  offals 
from  the  milling  of  wheat,  while  somewhat  more  nitrog- 
enous than  the  cereal  grains,  cannot  be  considered  as 
an  abundant  source  of  protein,  although  they  are  ex- 
cellent components  of  a  milk  ration. 

Notwithstanding  the  claims  which  trade  interests 
may  make  to  the  contrary,  no  one  of  the  above-men- 
tioned feeding  stuffs  is  alone  essential  to  the  economi- 
cal production  of  the  best  of  milk.  There  is  no  single 
food  or  any  one  combination  of  foods  that  is  always 
best  for  dairy  cows.  Apart  from  certain  considerations 
which  will  be  discussed  later,  a  selection  of  the  source 
of  commercial  protein  is  a  matter  of  availability  and 
of  relative  market  cost.  For  instance,  when  gluten 
meal  costs  $20  per  ton  few  buyers  can  afford  to  pay 
$27  for  linseed  meal  to  feed  in  any  considerable  quan- 
tity. If  prices  were  reversed,  oil  meal  should  be  se- 
lected. Both  oil  meals  and  gluten  products  may  be 
ignored  if  ground  peas,  buckwheat  middlings  or  the 
brewers'  residues  are  available  at  more  favorable  prices. 
It  is  simply  necessary  that  the  grain  ration  shall  con- 
tain protein  in  sufficient  quantity  and  proportion,  and 
shall  be  made  up  of  a  variety  of  materials,  better  not 
less  than  three  kinds,  all  of  .which  should  be  palatable 
and  exert  no  deleterious  influence  upon  the  milk  or  its 
products.  There  are  few  grain  products  that  cannot 
be  used  successfully  in  grain  mixtures,  even  though 
they  are  undesirable  when  fed  alone. 


316  The  Feeding  of  Animals 

THE     RELATION     OF     FOOD    TO     THE     COMPOSITION    AND 
QUALITY    OF    MILK 

There  is  a  widely  prevailing  opinioii  among  the 
farming  public  that  the  character  of  milk  is  inti- 
mately related  to  the  kind  and  quantity  of  food  from 
which  it  is  produced,  i.  e.,  that  a  dairyman  who  is 
possessed  of  sufficient  knowledge  may,  by  variations  in 
the  rations,  cause  material  changes  in  the  composition 
of  the  milk  of  his  herd.  This  is  equivalent  to  believ- 
ing that  thin  milk  or  rich  milk,  milk  rich  in  fats  and 
poor  in  casein  or  the  reverse,  may  be  obtained  at  the 
will  of  the  feeder.  Such  a  view  in  its  extreme  form 
is  very  far  from  the  truth.  While  below  a  certain 
limit  for  each  cow  the  quantity  of  milk  is  mostly  de- 
termined by  the  ration,  other  factors,  such  as  breed, 
individuality  and  period  of  lactation  are  much  more 
potent  than  the  food  in  fixing  its  composition. 

In  discussing  this  topic,  it  must  be  confessed  first 
of  all  that  the  experiments  touching  its  several  phases 
have  not  furnished  information  satisfactorily  definite 
and  conclusive  in  all  respects.  The  testimony  arrived 
at  is  more  or  less  confusing  and  contradictory.  There 
are  several  directions  in  which  it  has  been  necessary  to 
look  for  the  effect  of  food  upon  milk:  (1)  Effect  upon 
composition:  (a)  in  changing  the  proportion  of  water 
and  total  solid  matter;  {!))  in  changing  the  relative 
proportions  of  proteids,  fat  and  sugar;  (c)  in  changing 
the  constituents  of  the  fat.      (2)  Effect  upon  flavor. 

1.  (a)  Effect  of  food  upon  f he  composition  of  will-. — 
In  discussing  the   effect  of    food   upon  the   proportion 


Influence  of  Food  on   Kind  of  Milk  317 

of  total  solids,  the  question  is,  Can  the  richness  of 
milk  be  modified  by  changes  in  the  ration  ?  For  in- 
stance, is  the  milk  from  a  very  generous  food  supply 
richer  than  that  from  a  moderate  or  scanty  ration, 
or  will  a  highly  nitrogenous  ration  cause  a  secretion  of 
milk  with  a  higher  percentage  of  solids  than  a  ration 
poor  in  protein  ?  It  would  probably  be  generally  con- 
ceded that  if  variations  in  milk  are  caused  in  these 
ways,  they  are  small  as  compared  to  those  due  to 
breed  characteristics  or  to  individuality.  Can  we  bring 
about  variations  sufficiently  large  to  be  important  ? 
This  question  has  been  much  discussed  and  much  in- 
vestigated from  the  work  of  Kiihn  in  1868  down  to 
the  present  day.  Mau}^  experiments  have  been  con- 
ducted for  long  periods  and  short  periods  in  which 
very  moderate  rations  have  been  compared  with  very 
large  ones,  highly  nitrogenous  foods  with  those  of  a 
low  protein  content,  dry  with  green  or  succulent  ma- 
terials, and  grains  of  the  same  class  with  one  another, 
and,  in  a  great  majority  of  cases,  the  verdict  has  been 
that  "no  consistent  relation  appears  to  exist  between 
the  quantity  or  character  of  the  ration  and  the  com- 
position of  the  milk."  The  writer  has  examined  the 
results  of  nearly  all  the  important  experiments  of  this 
character  of  which  he  could  find  a  record,  and  in  but 
few  cases  could  he  discover  that  there  was  a  material 
increase  or  decrease  in  the  proportion  of  milk  solids 
which  bore  a  logical  relation  to  variations  in  the  ration. 
In  some  cases,  a  temporary  change  appeared  in  the 
milk  immediately  after  a  violent  change  in  the  ration, 
but    in    most    instances    of   this    kind,   there    was    very 


318  The  Feeding  of  Animals 

soon  a  return  to  the  animal's  normal  product.  In  a 
small  proportion  of  experiments,  the  milk  appeared  to 
sustain  a  permanent  though  not  extensive  modification. 
The  weight  of  testimon}^  bears  out  the  statement  that 
the  quality  of  milk  cannot  be  changed  at  will  by  the 
farmer,  but  is  largely  determined  by  causes  not  under 
his  control,  such  as  breed  and  individuality,  although 
feeding  and  treatment,  especially  the  latter,  have  more 
or  less  influence  upon  the  character  of  the  milk  secreted. 
It  is  possible,  even  probable,  that  continuous  feeding 
either  very  poorly  or  very  highly  may  bring  about  in 
time  a  permanent  change  in  a  cow's  milk,  but  to-day 
no  one  is  wise  enough  to  point  out  a  way  of  definitely 
controlling  this  product  through  the  food. 

{!))  In  the  discussions  relative  to  feeding  dairy  cows, 
another  point  has  received  much  attention;  viz.,  the 
effect  of  foods  upon  the  proportions  of  the  constitu- 
ents which  make  up  the  dry  matter  of  milk.  A  popu- 
lar notion  has  prevailed  that  it  is  possible  to  "feed 
fat  into  milk,"  having  its  origin  in  part,  perhaps,  in 
misconceptions  as  to  the  manner  of  milk  formation. 
If  the  mammary  gland  served  simply  to  capture  the 
unchanged  constituents  of  the  food,  then  it  might  be 
reasonable  to  expect  the  milk  to  partake  of  the  char- 
acter of  the  digested  nutrients  and  be  "fat"  or  "lean" 
according  to  the  proportions  of  proteids  and  fats  sup- 
plied to  the  animal.  When,  however,  we  consider  that 
this  gland  has  the  function  of  transforming  the  raw 
material  of  the  food  into  a  milk  which  is  characteris- 
tic of  the  breed  or  of  the  individual  in  accordance  with 
somewhat  fixed  constitutional  limitations,  and  that  from 


Influence  of  Food  on  Kind  of  MWk  319 

the  same  food  the  Jersey  cow  will  make  Jersey  milk 
and  the  Holsteiu  cow  Holstein  milk,  that  a  cow  which 
starts  in  life  giving  thin  milk  is  never  transformed  into 
a  producer  of  rich  milk,  we  can  easily  understand  the 
general  failure  to  find  a  recipe  for  feeding  fat  into  milk. 
Experimenters  who  have  added  large  quantities  of  fat 
or  oil  to  a  ration  have  in  all  but  a  very  few  instances 
failed  to  permanently  or  even  temporarily  increase  the 
percentage  of  fat  in  the  milk  solids;  and,  on  the  other 
hand,  rations  rich  in  protein  do  not  appear  to  cause  a 
larger  relative  amount  of  proteids  in  the  milk  dry  sub- 
stance than  rations  with  a  wide  nutritive  ratio.  As  a 
matter  of  fact,  after  years  of  investigation  and  intel- 
ligent observation,  we  are  not  able  to  affirm  that  the 
proportion  of  fat  to  other  milk  solids  is  in  any  way 
related  to  the  feeding  of  the  cow,  and  if  apparent  ex- 
ceptions to  the  general  experience  have  been  noticed,  no 
one  has  discovered  any  general  method  or  law  whereby 
the  exception  may  be  made  the  rule.  In  view  of  our 
present  knowledge,  certainly  no  more  absurd  view  pre- 
vails to-day  than  the  belief  that  the  composition  of 
the  milk  solids  is  subject  to  the  will  of  the  man  who 
feeds  the  cow. 

(c)  It  should  not  be  inferred  from  the  previous  state- 
ments that  none  of  the  compounds  of  the  food  enter 
the  milk  as  such,  or  that  the  qualities  of  the  milk  are 
in  no  way  influenced  by  the  character  of  the  ration. 
Such  conclusions  would  not  be  consistent  with  the  out- 
come of  numerous  investigations.  While  it  has  be- 
come quite  evident  that  the  composition  of  butter,  and 
therefore  its   qualities,  such    as   hardness   and   melting 


320  The  Feeding  of  Animals 

point,  are  sometimes  materially  modified  b}^  the  cow's 
food,  information  along  this  line  is  in  a  state  of  con- 
fusion and  inadeqnac}^  and  it  is  not  now  possible  to  state 
with  any  definiteness  just  what  influence  the  various 
feeding  stuffs  have  upon  the  chemical  and  physical 
properties  of  butter.  Experimenters  are  fairly  unani- 
mous, however,  in  concluding  that  the  liberal  feeding 
with  'cottonseed  or  cottonseed  meal  has  the  effect  of 
raising  the  melting  point  of  butter  and  of  diminishing 
the  percentage  of  the  volatile  fatty  acids.  On  the  other 
hand,  when  gluten  meal  rich  in  oil  has  been  intro- 
duced into  the  ration  in  generous  proportion,  the 
butter  has  been  found  to  melt  at  a  lower  point,  and 
appeared  softer.  Certain  chemical  reactions  indicate 
that  this  decrease  in  the  melting  point  has  been  accom- 
panied in  some  cases  at  least  by  an  increase  in  olein, 
a  fat  which  is  a  prominent  constituent  of  olive  oil, 
and  is  liquid  at  ordinary  temperatures.  One  set  of 
experiments,  where  gluten  meal  with  different  propor- 
tions of  oil  was  used,  appears  to  warrant  the  conclusion 
that  the  softening  of  the  butter  from  feeding  this  ma- 
terial is  not  marked  when  its  percentage  of  fat  is 
small,  as  is  the  case  with  some  brands  of  gluten  meal 
at  the  present  time.  The  conclusion  which  has  been 
reached  as  a  result  of  some  experiments,  that  gluten 
meal  causes  softer  butter  than  corn  meal,  the  fats  and 
other  compounds  in  the  two  feeds  being  similar  in 
kind,  is  wholly  irrational  unless  we  conclude  that  the 
larger  quantit}^  of  fat  fed  in  the  former  is  the  cause 
of  its  specific  influence.  In  a  few  cases  where  various 
oils    were    fed    in    liberal    quantity   the    butter   is    re- 


Influence  of  Food  on  Kind  of  Mill-  321 

ported  to  have  varied  in  ways  corresponding  to  the 
composition  of  the  oils,  a  result  not  at  all  inaprobable. 

In  looking  over  the  record  of  investigations  along 
tliis  line  it  is  found  that  food  rich  in  sugar  and  other 
soluble  carbohydrates  is  credited  with  producing  soft 
butter,  potatoes  are  charged  with  the  same  effect,  and 
even  cooked  or  sour  foods  are  said  to  have  a  peculiar 
influence.  Some  writers  go  so  far  as  to  present  lists 
of  feeding  stuffs  in  the  order  in  which  they  increase 
the  volatile  fatty  acids,  but  such  definite  representa- 
tions must  at  present  be  taken  ''with  a  grain  of  salt." 
In  most  instances,  no  relation  is  established  between 
the  effect  observed  and  the  market  value  of  the  butter. 
In  fact,  it  is  distinctly  asserted  by  one  or  two  experi- 
menters that  there  is  no  clear  relation  between  the 
melting  point  and  hardness.  It  seems  quite  probable 
that  when  the  ration  includes  a  variety  of  grain  foods, 
practically  the  entire  list  of  feeding  stuffs  may  be  uti- 
lized under  proper  conditions  without  damaging  the 
market  value  of  the  butter  for  local  consumption. 

2.  Effect  of  food  upon  the  flavors  of  milk  and  its 
products. —  It  is  not  possible  with  our  present  knowl- 
edge to  establish  a  relation  between  the  flavors  of  dairy 
products  and  the  presence  of  definite  compounds.  What- 
ever causes  flavor  in  milk  or  butter  is  generally  present 
in  such  minute  quantities  that  even  if  the  nature  of  the 
substance  was  known  the  determination  of  its  amount 
would  be  beyond  the  skill  of  the  chemist.  Milk  satis- 
factory to  the  critical  taste  and  smell  may  be  so  simply 
because  bad  flavors  are  absent,  or  there  may  be  pi^esenfc 
the  positive  iafluenge  of  gQm§  C9B§tittt§»t  qI  tb§  ratioa, 


322  The  Feeding  of  Animals 

It  is  probably  safe  to  assert  that  compounds  in  the  food 
may  pass  into  the  milk  as  such,  and  the  superiority  of 
June  butter*  if  such  exists,  may  be  due  to  the  almost 
imponderable  volatile  odors  which  are  derived  from  the 
young  grasses.  Nothing  is  more  certain  than  that  the 
deleterious  odors  of  certain  foods  and  those  that  per- 
tain to  the  stable  are  often  absorbed  by  milk,  as,  for 
instance,  when  cabbage,  turnips  and  onions  are  fed. 

It  is  generally  believed  that  odors  or  flavors  from 
the  foods  which  affect  milk  in  so  marked  a  manner 
may  enter  it  in  two  ways,  by  transference  through  the 
animal  and  by  absorption  from  the  air  of  the  stable. 
Unfortunately,  however,  the  various  views  which  are 
accepted  regarding  this  matter  are  not  based  upon  sat- 
isfactory experimental  evidence.  Some  farmers  declare 
in  most  positive  terras  that  they  can  feed  turnips  to 
their  cows  with  no  harm  to  the  quality  of  the  butter, 
while  others  assert  that  this  cannot  be  done.  It  is 
claimed  that  the  time  of  feeding,  whether  just  before 
or  just  after  milking,  has  a  marked  influence  upon  the 
extent  to  which  turnips  and  similar  materials  impart  a 
flavor  to  the  milk.  Concerning  all  these  points,  we 
have  but  little  evidence  other  than  the  somewhat  loose 
observations  of  practice. 

The  results  of  a  few  quite  recent  experiments  are 
worthy  of  mention  in  this  connection.  King  and  Far- 
rington,  of  the  Wisconsin  Experiment  Station,  declare 
that  their  experiments  show  beyond  question  that  when 
silage  is  fed  before  cows  are  milked  a  sweetish  flavor 
is  imparted  to  the  milk,  and  that  such  a  flavor  is  not 
detected  when  the  silage  is  fed  after  milking.     These 


Influence  of  Food  on  Kind  of  Milk  323 

experimenters  also  placed  milk  within  a  silo  exposed 
to  the  air  for  an  hour,  and  silo  air  was  forced  through 
the  contents  of  some  cans.  In  seven  out  of  twenty 
tests  no  silage  odor  could  be  detected,  and  it  was  less 
in  any  case  than  when  silage  was  fed  before  milking. 
Canadian  experiments,  on  the  effect  of  feeding  tur- 
nips, seemed  to  warrant  the  conclusion  that  the  mere 
presence  of  a  strong  turnip  flavor  in  the  stable  did  not 
affect  the  milk,  and  that  when  the  turnips  were  fed  in 
small  quantity  (one  peck)  daily  no  flavor  was  imparted, 
but  that  when  one  bushel  or  more  was  given  the  flavor 
appeared  whether  the  turnips  were  fed  before  milking 
or  after.  On  the  other  hand,  in  a  Norwegian  experi- 
ment as  high  as  2.8  bushels  of  turnips  were  fed  to 
cows  daily,  and  no  turnip  taste  could  be  detected  in 
the  milk.  The  cows  were  fed  in  one  place  and  milked 
in  another,  and  so  the  experimenter  concluded  that 
when  this  taste  is  observ^ed  it  is  due  to  absorption  by 
the  milk  after  it  is  drawn.  That  Avarm  milk  may  ab- 
sorb odors  is  shown  by  Russell.  These  observations 
illustrate  fairly  the  somewhat  inclusive  condition  of 
the  testimony  on  the  points  in  question. 


CHAPTER   XXII 

FEEDING    GROWING   ANIMALS 

A  DISCUSSION  of  rations  for  growing  animals  re- 
lates in  large  part  to  the  uses  of  food  for  constructive 
purposes.  The  formation  of  bone  and  soft  tissue  pro- 
ceeds rapidly  in  the  young  organism,  the  nutrition  of 
which  must  be  adapted  in  kind  and  quantity  to  large 
demands  in  this  direction.  This  is  true  of  all  young 
domestic  animals.  The  actual  daily  increase  in  live 
weight  of  a  well -nourished  calf  may  be  as  great  as 
that  of  a  mature  steer  when  liberally  fed.  It  is  not 
unusual  for  the  former  to  gain  two  pounds  a  day  in 
weight,  and  1.5  pounds  is  less  than  would  be  satis- 
factory. It  is  possible  to  calculate  approximately  what 
this  growth  would  require  of  actual  dry  matter.  The 
only  analysis  of  a  calf's  body  which  is  available  is 
that  made  by  Lawes  and  Gilbert,  from  which  it  ap- 
pears that  the  entire  animal  when  fat  has  approxi- 
mately the  following  composition  : 

Water  Ash  Protein  Fat 

%  %  %  % 

64.6     .   '  4.8  16.5  14.1 

A  gain  of  1.5  to  2  pounds  live  weight  means  a  storage 
of  not  less  than  .24  to  .38  of  a  pound  of  dry  protein  in 
the  animal's  body,  and  the  laying  on,  when  the  animal 

(324) 


Use  of  Food  hy    Groiving  Animal  325 

is  fed  for  fattening,  of  .21  to  .28  of  a  pound  of  actual 
fat.  Here,  then,  is  an  actual  daily  increase  of  dry 
body  substance  of  .45  to  .61  of  a  pound,  which  may  be 
equal  to  one -fifth  or  more  of  the  total  dry  substance 
of  the  ration. 

More  definite  information  is  furnished  hy  the  some- 
what limited  studies  which  have  been  made  of  the 
metabolism  of  the  calf.  As  long  ago  as  1878  Soxhlet 
studied  the  income  and  outgo  of  three  young  calves 
fed  on  whole  milk.  One  pound  of  milk  solids,  prac- 
tically all  digestible,  produced  one  pound  increase  of 
live  weight,  which  was  equivalent  to  a  storage  of  .at 
least  one -third  pound  of  body  dry  substance,  a  food 
efficiency  for  growth  practically  ten  times  that  exhib- 
ited with  animals  soiuewhat  mature.  Nearly  70  per 
cent  of  the  protein  of  the  food  was  fixed  in  the  bodies 
of  these  calves,  and  only  a  small  proportion  was  broken 
down,  conditions  quite  the  reverse  of  those  which  per- 
tain to  the  use  of  food  by  well -grown  steers.  Seventy- 
two  per  cent  of  the  phosphoric  acid  and  97  per  cent 
of  the  lime  were  retained  for  the  purposes  of  growth. 
Later  experiments  with  calves  fed  on  rations  in  whole 
or  in  part  composed  of  skim -milk,  show  a  deposit  of 
from  26  to  43  per  cent  of  the  protein.  These  results 
illustrate  the  vigor  with  which  a  young  animal  assimi- 
lates food  for  growth,  and  explain  the  greater  profits 
from  feeding  j'oung  animals  as  compared  with  feeding 
those  more  or  less  mature. 

During  recent  years  there  has  been  much  discussion 
and  many  experiments  touching  the  influence  of  food 
upon   the    development   of   the    animal   body.      Several 


326  The  Feeding  of  Animals 

experimenters,  notably  Sanborn  and  Henry,  in  this 
country,  have  compared  the  growth  of  swine  on  rations 
presenting  extreme  differences,  as,  for  instance,  mid- 
dlings and  blood  against  corn  meal  alone,  or  shorts 
and  bran  against  potatoes,  tallow  and  corn  meal.  As 
would  be  expected,  the  development  of  the  two  lots 
of  pigs  was  in  these  cases  greatly  unlike.  Those  fed 
on  the  nitrogenous  rations  contained  more  blood  than 
the  other ;  their  organs,  such  as  the  kidneys  and  liver, 
were  much  larger  in  proportion  to  the  weight  of  the 
body,  the  bones  were  stronger  and  the  proportion  of 
muscle  in  the  carcass  was  much  greater.  These  differ- 
ences were  very  marked.  It  should  not  be  forgotten, 
however,  that  these  were  extreme  and  somewhat  un- 
usual rations.  It  is  doubtful  whether  there  are  gen- 
erallj^  sufficient  differences  in  the  food  combinations  of 
ordinarj^  practice  to  occasion  such  marked  differences 
of  body  structure. 

At  the  Cornell  University  Experiment  Station  lambs 
fed  on  oil  meal  and  bran  made  a  mnch  more  satisfac- 
tory gain  than  a  lot  the  grain  ration  of  which  was 
corn  meal  alone,  but  the  photographs  of  the  carcasses 
do  not  show  a  larger  proportionate  growth  of  muscular 
tissue  from  the  nitrogenous  foods. 

An  elaborate  stud.y  of  the  influence  of  the  ration 
upon  the  coniposition  of  the  carcass  w^as  made  at  the 
Maine  Experiment  Station,  where  two  lots  of  steers 
were  fed  from  calfhood  on  rations  widely  unlike  in 
their  nutritive  ratio.  The  grain  food  of  one  lot  was 
oil  meal,  wheat  bran  and  corn  meal,  and  of  the  other 
lot    corn    meal,   mixed  with    a  minimum   proportion  of 


Relation   of  Food  to    Character  of  Growth      327 

wheat  bran,  the  nutritive  ratios  being  respectively  1:5.2 
and  1:9.7.  One  animal  from  each  lot  was  killed  at  the 
end  of  seventeen  months  of  feeding  and  the  others  at 
the  end  of  twenty -seven  months,  the  entire  bodies  of 
the  four  steers,  exclusive  of  the  skins,  being  analyzed. 
It  was  found  that  the  composition  of  the  several  ani- 
mals did  not  differ  materially.  The  amount  of  growth 
was  at  first  more  rapid  with  the  more  nitrogenous 
ration,  but  the  kind  of  growth  appeared  to  have  been 
controlled  by  the  somewhat  fixed  constitutional  habits 
of  the  breed.  Nevertheless,  the  evidence  of  all  well- 
conducted  experiments  and  of  all  experience  is  unani- 
mous in  emphasizing  the  necessity  of  supplying  in  the 
food  of  young  animals  an  abundance  of  those  nutrients 
which  are  needed  for  the  building  of  bone  and  muscle. 
A  satisfactory  development  of  the  organism  at  maturity 
is  insured  only  when  the  early  growth  is  liberal  and 
uniform,  and  is  such  as  to  produce  strong  bone  and  a 
vigorous  muscular  system.  More  than  this,  there  is 
induced  by  proper  nourishment  a  lively  temperament 
or  energy  of  body  that  may  be  called  vital  force,  which 
chemical  analysis  cannot  search  out  or  measure,  but 
which  gives  the  chief  value  to  certain  classes  of  ani- 
mals and  is  desirable  in  all.  It  is  believed  that  this 
condition  of  strong  vitality  is  promoted  by  a  liberal 
supply  of  the  proteids  in  the  food. 

In  considering  the  feeding  of  young  animals,  we 
recognize  the  mother's  milk  as  in  general  supplying 
the  necessar}'  nutrients  in  the  best  forms  and  propor- 
tions. It  is  true  in  the  case  of  cows  that  the  very 
rich   milk   of    the    butter    breeds    when    generously  fed 


328  The  Feeding  of  Animals 

often  causes  a  serious  disturbance  of  the  calf's  diges- 
tive organs,  but  the  fact  remains  that  casein,  milk  fat 
and  milk  sugar  are  adapted  through  Nature's  design 
to  the  digestive  processes  and  the  nutrition  of  young 
animals.  Moreover,  milk  is  rich  in  the  mineral  com- 
pounds needed  for  bone  formation.  When,  therefore, 
it  becomes  necessary  or  desirable  to  substitute  other 
food  for  the  mother's  milk,  it  is  essential  not  to  act 
counter  to  phj^siological  necessities  and  conditions. 

One  fact  of  importance  is  that  the  very  young  ani- 
mal is  somewhat  undeveloped  in  its  capacity  to  digest 
the  starchy  grains  and  similar  substances,  the  secre- 
tions necessary  for  this  purpose  not  yet  being  abundant. 
It  follows,  then,  that  the  first  substitute  for  whole 
milk  should  not  consist  largely  of  the  insoluble  carbohy- 
drates, like  porridge  from  any  of  the  cereals.  Again, 
the  young  animal's  stomach  is  at  first  unfitted  for  re- 
ceiving and  utilizing  bulky,  fibrous  food.  Some  time 
must  elapse  before  the  calf  or  colt  can  be  expected 
to  obtain  much  nourishment  from  grass,  hay  or  like 
materials. 

THE     FEEDING     OF     CALVES 

The  most  successful  way  of  feeding  calves  to  secure 
rapid  growth,  especially  to  produce  veal  of  the  highest 
qualit}',  is  to  supply  them  with  the  mother's  milk  up 
to  the  limit  of  their  capacity.  Where  they  are  to  be 
raised  for  stock  purposes,  satisfaetorj'  growth  may  be 
maintained  with  the  use  of  substitutes  for  whole  milk, 
which  is  fortunate,  because  with  the  exception  of  the 
western    plains,  where    cows    are    cheaply  kept    simply 


Food  for  the    Calf  329 

for  breeding  purposes,  or  where  a  breeder  is  selling 
his  increase  at  fancj'  prices,  the  feeding-  of  whole  milk 
is  not  warranted  by  the  value  of  the  resulting  animal. 

For  this  reason,  most  dairymen,  particularly  those 
who  sell  milk  as  such,  kill  the  calves  at  the  age  of  a 
few  days,  excepting  perhaps  during  that  portion  of  the 
year  when  veal  sells  at  a  very  high  price.  On  the 
other  hand,  many  dairymen  who  have  a  supply  of 
skimmed  milk,  successfully  feed  this  to  growing  calves, 
when  it  is  desired  to  raise  heifers  or  even  steers.  Ex- 
perience has  shown  that  it  is  entirely  practical  to  do 
this,  and  it  is  certainly  economical,  for  experiments 
have  demonstrated  that  as  prices  average,  the  cost  of 
a  pound  of  growth  so  produced  is  about  one -third 
what  it  would  be  if  whole  milk  were  fed. 

As  a  guide  in  providing  a  substitute  for  whole 
milk,  it  may  be  stated  that  a  vigorous  calf  should 
verj'  early  be  made  to  eat  daily  not  less  than  three 
pounds  of  highly  digestible  matter  with  a  nutritive 
ratio  at  first  not  wider  than  that  of  whole  milk  solids. 
The  exclusive  feeding  of  skimmed  milk  for  anj^  length 
of  time  is  not  to  be  recommended.  Experience  shows 
that  for  young  calves  it  should  be  so  combined  with 
other  materials  that*  a  mixture  is  obtained  which,  so 
far  as  possible,  resembles  whole  milk  in  its  nutritive 
ratio.  After  the  fat  is  removed  from  the  milk,  the  non- 
nitrogenous  compounds  are  probably  not  present  in 
sufficient  proportion  to  protect  the  pi'otein  from  waste 
as  fuel.  No  feeding  stuff  appears  to  be  a  more  effi- 
cient amendment  of  skimmed  milk  for  the  earliest 
feeding   than    flaxseed    meal    cooked   into    a    porridge. 


330  The  Feeding  of  Animals 

The  explanation  of  this  is  the  high  percentage  of  oil 
in  this  meal,  its  low  content  of  starch,  and  its  high 
rate  of  digestibility.  Besides,  it  appears  to  promote  a 
healthy  condition  of  the  organs  of  digestion.  Oil  meal 
may  be  used  in  its  stead,  but  it  is  less  desirable  at 
first. 

The  calf  should  be  allowed  whole  milk  for  a  few 
days,  not  necessarily  more  than  a  week,  when  it  may 
be  gradually  changed  over  to  skimmed  milk  and  flax- 
seed meal.  An  admirable  mixture  is  prepared  by 
cooking  the  flaxseed  meal  in  water  in  the  proportion 
of  one  to  six  by  volume,  and  adding  a  small  amount  of 
this  (the  equivalent  of  three  or  four  tablespoonfiils 
of  the  dry  meal  at  first)  to  eighteen  or  twenty  pounds 
of  warm  skimmed  milk,  which  may  serve  as  a  day's 
ration.  The  quantity  of  meal  should  be  gradually  in- 
creased up  to  one  pound  a  day  inside  of  a  few  weeks. 
In  six  or  eight  weeks  the  calf  should  be  allowed  ac- 
cess to  dry  oatmeal,  or  oatmeal  and  wheat  middlings,  or 
the  oatmeal  and  middlings  may  be  boiled  with  the 
flaxseed  meal  and  mixed  with  the  milk.  After  ninety 
days  the  flaxseed  meal  may  be  dropped  for  the  sake  of 
economy.  The  calf  will  soon  appreciate  a  wisp  of 
early  cut  hay,  some  coarse  food  "becoming  a  necessity 
before  many  months  pass.  This  method  of  feeding 
has  repeatedly  produced  rapid  growth  and  fine  ani- 
mals. For  heifers  it  is  probably  to  be  preferred  to 
whole  milk  feeding,  as  it  is  fully  as  conducive  to  the 
vigorous  development  of  the  muscular  system  and  is 
less  likely,  perhaps,  to  promote  a  tendency  to  lay  on 
body  fat. 


Feeding  Lambs  for  Rapid   Growth  331 

Hay  tea  is  sometimes  used  as  a  milk  substitute, 
but  it  is  a  poor  oue.  Only  a  small  proportion  of  the 
nutrients  of  hay  is  soluble,  and  the  water  extract  is 
a  dilute  and  comparatively  innutritions  food  for  a  grow- 
ing animal,  the  use  of  which  can  be  justified  only  in  the 
absence  of  milk  in  any  form,  and  which,  when  used, 
must  be  very  liberally  fortified  by  grain  feeds. 

THE    FEEDING    OF    LAMBS 

The  first  growth  of  lambs  is  chiefly  fi-om  the  moth- 
er's milk,  and  we  have  little  occasion  to  consider  sub- 
stitutes for  this  food.  The  fact  first  in  order  and  most 
important  in  this  connection  is  that  well-fed  mothers 
are  absolutely  essential  to  rapid  growth.  A  lamb  must 
be  fed  through  its  dam.  Nothing  is  more  pitiable  than 
the  sight  of  a  pair  of  hungry  twin  lambs  making  an 
effort  to  satisfy  their  insistent  demands  for  groAvth 
with  the  milk  furnished  by  a  small,  lean,  under- fed 
mother.  It  is  a  repetition  of  the  cruel  command  to 
"make  bricks  without  straw."  As  a  matter  of  fact,  the 
treatment  of  the  ewe  before  the  birth  of  her  young 
should  be  such  as  to  prepare  her  for  the  strain  of 
supplying  a  generous  flow  of  milk. 

Ewes  that  are  suckling  lambs,  Avhile  fed  from  the 
barn,  should  be  supplied  with  good  clover  or  alfalfa 
hay,  or  hay  from  fine  mixed  grasses.  Pea  and  bean 
straws  are  excellent  coarse  feeds  for  sheep.  Timothy 
hay  is  an  abomination  as  sheep  food,  especially  under 
these  conditions.  The  grain  ration  should  not  be  less 
than  three -fourths  of  a  pound  daily,  made  up  in  part 


332  The  Feeding  of  Animals 

of  one  or  more  of  the  highlj^  nitrogenous  feeding  stuffs. 
It  is  also  desirable  to  feed  a  small  proportion  of  some 
succulent  food.  What  is  needed  is  a  milk- producing 
ration,  and  the  discussion  of  feeding  cows  for  milk 
production  in  a  i)receding  chapter  is  in  part  pertinent 
to  ewes.  Corn,  oats,  wheat  bran  or  middlings,  beans, 
peas,  gluten  and  oil  meals  are  all  useful  in  making  up 
such  a  ration.  With  safe  feeding  one  pound  dailj^  of 
a  mixture  of  oil  or  gluten  meal,  one  part,  wheat  bran, 
two  parts,  and  corn  meal,  two  parts,  combined  with 
two  or  three  pounds  of  roots  or  silage  and  what  coarse 
feed  the  appetite  will  bear,  is  a  good  milk  ration,  and 
will  bring  the  ewes  through  the  strain  of  suckling 
lambs  in  good  condition.  If  it  is  desired  to  produce 
the  most  rapid  growth  of  the  lambs,  they  should  also 
have  access  from  nearly  the  first  to  a  grain  mixture. 
Experiments  indicate  that  this  mixture  is  most  eco- 
nomical, especially  if  the  lambs  are  to  be  fed  later  for 
the  market,  when  containing  a  generous  proportion  of 
corn  meal,  to  which  may  be  added,  among  other  mate- 
rials, ground  oats,  wheat  bran,  gluten  feed  or  meal,  or 
oil  meal,  reference  being  had  to  the  ruling  market  prices. 
In  an  experiment  at  the  Maine  Experiment  Station 
lambs  suckled  by  grain -fed  mothers  and  with  access 
to  grain  themselves  made  75  per  cent  or  more  gain 
in  live  weight  than  those  did  that  received  no  grain 
and  which  were  suckled  by  mothers  that  ate  a  limited . 
grain  ration.  Five  and  three-fourths  pounds  of  grain 
produced  one  pound  of  growth.  At  the  Wisconsin 
Experiment  Station,  as  an  average  of  three  trials,  lambs 
fed  grain  before  weaning  gained  in  ten  to  twelve  weeks 


Qualities   Demanded  in  Horses  333 

seven  and  a  half  pounds  more  each  than  those  not  so 
fed.  Four  pounds  of  grain  produced  one  pound  of 
live  weight. 

'  Liberal  feeding  means  more  economical  growth,  a 
higher  qualitj'  of  product  and  the  earliest  possible  mar- 
ket. The  foregoing  discussion  is  applicable  to  the 
raising  of  earlj^  lambs.  If,  however,  they  are  dropped 
during  the  grazing  season,  where  the  ewes  have  abun- 
dant pasturage,  the  question  of  feeding  is  simplified,  for 
no  ration  is  more  promotive  of  abundant  milk  secre- 
tion than  young  grass;  besides,  the  low  price  at  which 
late  lambs  are  usually  sold  does  not  encourage  exten- 
sive grain  feeding.  When  lambs  are  grown  for  breed- 
ing stock  their  early  grain  rations  should  be  lighter, 
and  may  properly  consist  more  largely  of  oats  and 
bran,  with  a  smaller  proportion  of  corn. 

FEEDING    COLTS 

The  value  of  a  horse  for  either  draft  or  road  pur- 
poses is  greatly  dependent  upon  those  physical  qualities 
which  secure  vigor  and  endurance.  A  horse  is  not 
regarded  as  desirable  that  is  devoid  of  "nerve"  and 
that  cannot  sustain,  if  necessary,  the  strain  of  hard, 
or  even  severe,  work;  and  breeders  seek  to  produce 
animals  having  these  characteristics.  Two  main  factors 
are  involved  in  the  proper  physical  development  of 
the  colt:  food  and  exercise.  The  latter  is  a  part  of 
the  general  management  to  which  the  horse  breeder 
must  give  detailed  attention  and  wdll  not  be  discussed 
la    this    couaection.     The    technics    with    which    the 


334  The  Feeding  of  Animals 

horseman  should  be  familiar  must  be  learned  through 
experience  and  by  consulting-  special  literature. 

It  is  proper  to  state  that  our  knowledge  concerning 
the  feeding  of  colts  consists  largely  of  the  conclusions 
derived  from  experience  of  practical  men.  Very  little 
experimental  attention  has  been  given  to  this  subject 
by  investigators.  Duriug  the  twenty-five  years  that 
experiment  stations  have  existed  in  the  United  States 
only  two  stations  have  reported  experiments  along  this 
line,  and  these  were  not  extensive;  but  notwithstanding 
the  lack  of  direct  data  from  scientific  sources  there  are 
well  proven  and  safe  facts  to  which  we  can  refer. 

Feeding  the  dam. — The  proper  feeding  of  the  young 
foal  is  accomplished  first  through  the  proper  feeding 
of  the  dam.  The  mare  with  a  colt  at  her  side  should 
be  regarded  as  a  milch  animal,  making  demands  upon 
the  food  for  generous  milk  production  similar  to  those 
made  by  the  milch  cow.  This  is  equivalent  to  the 
statement  that  when  suckling  her  foal  the  dam  should 
be  given  foods  that  stimulate  milk  secretion.  If  she 
is  allowed  the  run  of  a  good  pasture  both  mother  and 
colt  will  usually  thrive  satisfactorily.  Young  pasture 
grass  is  as  efficient  with  the  mare  as  with  the  cow. 
If,  on  the  other  hand,  the  feeding  is  from  the  stable, 
either  wholly  or  to  amend  an  insufficient  or  inferior 
food  supply  from  grazing,  then  the  grain  ration  should 
be  made  to  include  such  feeding  stuffs  as  barlej%  oats, 
wheat,  wheat  bran,  wheat  middlings,  peas,  and  even 
a  small  proportion  of  linseed  meal.  Whenever  soiling 
cfops  are  grown  these  may  be  fed,  especially  alfalfa. 
In  case  the  legume  fodders  are  available,  either  green 


Gram   Foods  for    Colts  335 

or  dried,  the  necessity  for  protein  in  the  grain  is  not 
so  great  and  corn  may  form  a  larger  proportion  of  the 
ration. 

A  good  grain  mixture  for  ordinary  conditions  would 
be  cracked  corn  two  parts,  wheat  bran  seven  parts 
and  linseed  meal  one  part;  or  ground  oats  four  parts, 
wheat  middlings  five  parts  and  linseed  meal  one  part. 

Feeding  tJie  colt. —  Before  the  colt  is  weaned,  with 
good  management,  he  will  learn  to  eat  grain,  which  is 
very  likely  to  be  the  same  mixture  as  that  eaten  by 
the  dam.  If  desired,  an  enclosure  may  be  built,  into 
which  the  colt  and  not  the  mother  can  pass,  where  a 
special  grain  food  may  be  provided.  This  brings  us 
to  the  consideration  of  what  shall  be  the  grain  ration 
of  the  colt,  both  before  and  after  weaning. 

The  opinion  is  generally  held  that  oats  are  superior 
to  all  other  feeding  stuffs  as  horse  food,  particularly 
for  the  development  of  those  qualities  of  temperament 
and  muscle  which  are  regarded  as  so  desirable,  espe- 
cially in  a  carriage  horse.  It  is  recognized,  of  course, 
that  oats  are  comparatively  costly,  but  it  is  claimed 
that  the  superior  results,  whether  in  the  kind  of  devel- 
opment of  the  colt  or  in  the  quality  of  service  of  the 
mature  animal,  justify  their  use.  An  opinion  so  uni- 
versally entertained  is  not  wisely  ignored.  It  has  been 
shown  many  times,  however,  that  popular  views  have 
been  wholly  or  in  part  erroneous,  or,  at  least,  have 
been  based  upon  wrong  premises;  and  in  this  partic- 
ular case  certain  statements  are  currently  accepted  as 
facts  which  have  no  well-established  basis. 

Reference  is  frequently  made  to  the  tonic  effect  of 


336  The  Feeding  of  Animals 

oats,  and  there  appears  to  be  a  popular  notion  abroad 
that  this  grain  contains  a  peculiar  compound  which 
acts  as  a  nerve  stimulant  and  imparts  "  life "  to  the 
horse. 

No  chemical  facts  to  support  this  view  can  be  cited. 
To  be  sure,  it  was  announced  in  1883  that  Sanson  had 
discovered  in  oats  a  characteristic  alkaloid  having  a 
stimulating  effect  upon  the  motor  nerves  of  the  horse, 
but  subsequent  elaborate  investigations  b}^  Wrampel- 
myer  failed  to  verify  Sanson's  conclusions.  Notwith- 
standing the  fact  that  the  oat  kernel  has  been  the 
subject  of  very  careful  chemical  studies,  no  chemist 
has  yet  discovered  that  it  contains  any  compounds  so 
characteristically  unlike  those  of  other  grains  as  to 
account  for  an  unusual  influence  upon  the  nervous 
system,  or  for  a  superior  development  of  the  muscles. 

There  does  not  appear  to  be  on  record  testimony 
of  a  more  convincing  character  concerning  the  stimu- 
lative influence  of  oats  than  opinions,  partly  traditional 
and  partly  the  result  of  not  very  exact  practical  obser- 
vations. While  it  is  certainly  not  easy  to  present  a 
definite  and  satisfactory  explanation  of  the  existence  of 
these  opinions,  it  may  be  suggested  that  the  "life,"  or 
nervous  condition,  of  a  horse  is  a  resultant  of  several 
factors  or  influences.  These  are  the  quantity  of  diges- 
tible food  supplied,  the  proportion  of  protein  in  the 
ration,  the  condition  of  the  digestive  tract,  care,  exer- 
cise, and  all  the  many  small  influences  which  affect 
health.  In  those  instances  where  feeding  oats  has 
seemed  to  improve  the  performance  of  the  horse,  even 
if  tliis  bfts  actually  occurred,  we  have  mo  aasurauc^ 


Oats   vs.  other    Grains  337 

that  in  changing  the  ration  the  amount  and  proportions 
of  the  nutrients  digested  have  remained  the  same.  It 
is  probable  that  usually  comparisons  have  been  made 
between  oats  and  corn,  and  whenever  this  has  been 
done  it  is  not  necessary  to  refer  the  better  effect  of 
the  former  to  the  existence  of  compounds  having  tonic 
properties.  The  w^ell-knowni  differences  in  the  gen- 
eral composition  of  the  two  grains  Avill  in  part  account 
for  the  more  satisfactory  condition  of  the  animal  when 
the  oats  are  fed.  With  the  liberal  feeding  of  corn 
there  is  a  tendency  towards  the  laying  on  of  fat,  and 
a  greater  likelihood  of  imperfect  digestion,  because  of 
the  high  proportion  of  carbohydrates  and  the  liability 
of  undesirable  fermentations.  It  seems  entirely  prob- 
able that  if  thorough  comparison  could  be  made  be- 
tween oats  and  the  best  grain  mixtures  which  could 
be  suggested  in  the  light  of  present  knowledge,  the 
oats  would  not  maintain  so  great  a  superiority  over 
other  feeds  for  growing  colts  as  is  now  generally  at- 
tributed to  them.  The  few  experiments  which  have 
been  made  indicate  that  for  producing  rapid  growth 
oats  were  inferior  to  either  a  mixture  of  peas  and 
middlings,  or  to  a  mixture  of  middlings,  gluten  meal 
and  linseed  meal;  but  these  observations  were  not 
carried  far  enough  to  determine  the  relative  effect  upon 
the  quality  of  the  animal. 

Whatever  may  be  the  whole  truth  in  this  matter, 
doubtless  all  necessary  conditions  for  producing  growth 
and  qualitj'  in  colts  would  be  met  by  a  ration  of  which 
oats  form  a  part.  The  following  mixtures  are  sug- 
gested as  illustrative  of  good  ones: 


338  The  Feeding  of  Animals 

Mixture  1  Mixture  2 

Oats 4  parts      Corn 2  parts 

Bran  or  middlings  •  .4  parts       Oats 4  parts 

Peas 2  parts      Bran 3  parts 

Oil  meal 1  part 

These  mixtures  are  generally  less  expensive  than 
oats  alone,  and  in  kind  fully  meet  the  demands  for 
growth  of  both  bone  and  muscle. 

Henry  gives  as  a  fair  allowance  of  grain  for  a  colt, 
measured  in  oats,  the  following  quantities:  Up  to  one 
year  of  age,  two  to  three  pounds;  from  one  to  two 
years,  four  to  five  pounds;  from  two  to  three  years, 
seven  to  eight  pounds.  In  using  the  other  grain  feeds 
suggested,  which  mostly  have  a  higher  rate  of  digesti- 
bility than  oats,  no  larger  quantities  would  be  neces- 
sary. Skim  milk  may  be  fed  to  colts  in  limited  amounts 
with  good  results,  as  experiments  show.  Feeding  it 
in  quantities  sufficient  to  force  rapid  grow^th  is  to  be 
deplored. 

It  is  generally  conceded  that  the  colt  should  be 
allowed  to  eat  a  reasonable  proportion  of  coarse  feed 
as  a  means  of  properly  developing  the  digestive  tract. 
It  is  entirely  possible  to  supply  concentrated  grains 
too  freely,  to  the  exclusion  of  more  bulky  materials, 
and  in  that  way  fail  to  secure  a  desirable  distension  of 
the  alimentary  canal.  This  does  not  mean  that  the 
colt  should  be  allowed  to  gorge  himself  with  hay  or 
other  coarse  material,  as  an  unfortunate  extreme  in 
this  direction  is  easil3'   reached. 


CHAPTER    XXIII 

FEEDING    ANIMALS    FOB    THE    PRODUCTION    OF    MEAT 

The  production  of  beef  was  at  one  time  a  source 
of  income  to  nearl}^  all  farms.  In  earlier  days  the  New- 
England  farmer  annually  sent  to  the  market  a  few  fat 
steers  or  oxen.  At  the  present  time  the  beef  consumed 
in  the  United  States  and  that  exported  comes  very 
largely  from  the  wide  grazing  areas  of  the  west-,  where 
the  cost  of  feed  and  the  necessary  amount  of  labor 
are  at  a  minimum.  The  reasons  for  this  change  are 
not  hard  to  find.  The  food  cost  of  beef -making  is 
relatively  large  as  compared  with  dairy  products,  and 
in  the  east  the  growth  of  home  markets  for  milk  and 
cream  has  made  it  possible  for  farmers  to  turn  their 
high  cost  feeding  stuff  into  products  having  a  higher 
proportionate  market  price  than  beef.  Moreover,  cer- 
tain eastern  lands  have,  with  enlarging  markets,  been 
occupied  to  good  advantage  with  fruit  and  vegetables. 
Doubtless  the  time  will  come,  after  the  wide  areas  of 
the  west  are  more  densely  peopled,  when  beef  produc- 
tion will  receive  more  attention  in  the  eastern  states. 
Some  farmers  find  it  profitable  there  even  now.  It  is 
certain  that  it  involves  good  judgment,  skill  and  the 
art  of  feeding  to  the  highest  degree,  especially  if  it 
is  to  secure  fair  returns  against  western  competition. 

(339) 


340  The  Feeding  of  Animals 

The  breeding  or  selection  of  animals  of  the  most  prof- 
itable tj'pe  that  will  supply  the  market  with  a  high- 
grade  product,  and  stable  feeding,  so  as  to  produce 
rapid  and  continuous  increase  without  disease  or  disas- 
ter of  any  kind,  require  experience  and  an  intelligent 
application  of  all  the  factors  involved. 


THE  NATUEE  AND  EXTENT  OF  THE  GROWTH  IN  BEEF 
PRODUCTION 

Feeding  steers  or  oxen  for  the  market  may  be  car- 
ried on  with  young  animals  that  are  still  making  some 
growth  of  bone  and  muscle,  or  with  those  so  mature  that 
additional  weight  comes  almost  wholly  from  a  deposi- 
tion of  fat  in  the  tissues  already  formed.  This  is  the 
difference  between  feeding  a  two -year -old  and  a  five- 
year -old  steer.  In  either  case  the  predominating  con- 
stituent of  the  increase  is  fat.  This  fact  is  established 
by  the  investigation  of  Lawes  and  Gilbert  and  by  one 
experiment  in  this  country.  Dr.  Gilbert  in  his  lec- 
tures summarizing  the  Rothamsted  work  gives  the 
following  figures: 

Couiposition  of  increase  wlien  steers  are  fattening 

Water  Ash  Protein  Fat 

%  %  %  % 

Oxen  fattened  very  young 32-37  2%  10  50-55 

Matured  animals,  final  period 25-30  1%  7-8  60-65 

American  results  with  well-fed 
steers,  growth  from  17  mos.  to 
27  mos.  of  age 42.4  6.  14.1  37.5 

These  figures  may  be  regarded  as  reliable,  and  they 
show   most   conclusively    that   in   beef   production    the 


Food    Needs    of  Fattening    Steers  341 

constructive  use  of  the  food  is  largely  in  the  direction 
of  fat -forming. 

The  extent  of  the  actual  production  which  occurs 
can  be  closely  estimated  for  any  given  case.  It  is 
considered  satisfactory  if  the  rate  of  increase  during 
a  reasonably  long  period  of  fattening  is  2  lbs.  live 
weight  per  day.  This  means  the  actual  addition  to 
the  dry  substance  of  the  body  of  from  1.3  to  1.5  lbs. 
Sometimes  during  short  periods  with  excessive  feeding 
the  daily  gain  may  be  3  lbs.  live  weight,  and  generally 
after  animals  are  well  fattened,  during  the  finishing 
period,  it  may  be  as  low  as  1  lb.  or  less.  The  actual 
daily  growth  of  new  material  may  vary  then,  aside 
from  the  water,  from  .G  to  2.25  lbs.  per  day.  Actual 
fat  formation  may  thus  range  from  .4  to  1.8  lbs.  per 
day.  The  proteid  content  of  the  increase,  on  the  other 
hand,  probably  does  not  exceed  .3  lb.  daily  in  any  in- 
stance, and  with  mature  animals  it  is  very  insignificant. 

The  food  needs  of  the  fattening  steer. —  In  view  of 
the  foregoing  facts  and  of  the  prevailing  views  as  to 
the  fat -forming  function  of  carbohydrates,  we  can  but 
conclude  that  the  non- protein  part  of  the  ration  maj^ 
be  the  source  of  the  chief  part  of  the  body  substance 
laid  on  by  a  fattening  steer.  The  amount  of  protein 
necessary  for  constructive  work  seems  to  be  very  small 
—  with  mature  animals  it  is  practically  nothing.  Our 
theoretical  point  of  view  as  to  the  nutrients  which  will 
serve  the  purposes  of  a  fattening  animal  is  therefore 
quite  different  from  what  it  was  when  eminent  author- 
ities regarded  protein  as  the  main  source  of  body  fat. 
It  would  seem,  looking  at  the  matter  merely  from  the 


342  The  Feeding  of  Animals 

staudpoiiit  of  the  demands  for  groAvth,  that  in  feeding 
fairly  mature  animals  for  beef  production  a  ration  may 
be  efficient  with  a  wide  nutritive  ratio,  much  wider  than 
what  is  recommended  in  the  German  standards. 

It  is  recognized,  though,  that  we  cannot  decide  upon 
a  ration  merely  upon  the  basis  of  the  raw  materials 
that  are  needed  for  constructive  purposes.  The  influ- 
ence of  a  particular  feed  or  of  a  variety  of  feeds  upon 
the  appetite  and  upon  what  we  speak  of  as  general 
condition,  as  well  as  upon  the  quality  of  the  product, 
and  the  necessity  of  avoiding  so  large  a  preponderance 
of  carbohydrates  as  to  cause  a  possible  depression  of 
digestibility  are  all  points  which  must  be  considered 
in  determining  the  value  of  a  ration.  We  should  re- 
member also  that  the  stimulating  effect  of  the  food 
upon  the  vital  functions  is  a  factor  in  successful  feed- 
ing. So,  after  all,  we  must  appeal  to  experience,  scien- 
tific and  practical,  for  information  as  to  what  rations 
are  efficient  for  fattening  purposes. 

The  German  standard  rations  for  fattening  bovines 
which  are  at  present  recommended  call  for  18  to  18.4 
lbs.  of  digestible  organic  matter  daily  for  each  1,000 
lbs.  of  live  weight,  with  a  ratio  of  1:5.4  to  1:6.5, 
requiring  from  2.5  to  3  lbs.  of  digestible  protein.  If 
protein  was  regarded  as  taking  a  prominent  part  in 
fat-building  and  in  sustaining  muscular  activity,  as 
was  once  held,  this  standard  might  seem  rational,  but 
in  view  of  more  recent  scientific  conclusions  concern- 
ing the  functions  of  nutrients  it  is  not  easy  to  under- 
stand why  a  fattening  steer  requires  more  protein  than 
a  milch  cow  or  even  as  much. 


Proportion   of  Protein   in   Fattening   Ration       343 

It  is  gratifying  to  discover  that  feeding  experi- 
ments with  fattening  oxen,  conducted  under  the  im- 
proved methods  of  research,  give  results  not  inconsist- 
ent with  the  facts  to  which  attention  has  been  called. 
Kellner  very  ably  discusses  a  large  number  of  such 
experiments,  made  by  himself  and  associates  with  the 
aid  of  the  respiration  apparatus,  and  he  emphatically 
declares  that  the  nutritive  ratio  of  a  fattening  ration 
may  vary  from  1:4  to  1:10  without  affecting  the 
increase  of  body  substance  from  a  unit  of  digestible 
food  material,  provided,  however,  that  the  nutrients 
supplied  above  maintenance  needs  shall  come  from 
the  more  easily  digestible  feeding  stuffs.  He  cites,  in 
the  support  of  his  conclusion,  the  outcome  of  nineteen 
previous  experiments  bj^  Wolff,  in  which  rations  va- 
lying  in  nutritive  ratio  from  1:4  to  1:9.5  showed 
no  material  differences  in  the  efficiencj'  of  a  unit  of 
digestible  matter.  It  seems,  then,  that  scientists  are 
coming  to  agree  that  a  wide  nutritive  ratio  is  not 
inconsistent  with  most  successful  feeding  of  fattening 
steers,  especially  those  that  are  mature.  If  the  ani- 
mals are  so  young  as  to  be  making  material  growth, 
then  it  is  conceded  that  there  is  more  reason  for  avoid- 
ing a  very  wide  ratio. 

Among  the  practical  feeding  experiments  conducted 
in  the  United  States,  there  are  several  instances  where 
the  wide  ratio  rations  have  been  found  equal  to  the 
more  nitrogenous.  On  the  other  hand,  and  perhaps 
in  a  majority  of  experiments,  the  rations  containing 
the  largest  proportion  of  protein  have  caused  the  most 
rapid  growth.     In  1893  the  writer  made  a  careful  study 


344  The  Feeding  of  Animals 

of  many  previous  experiments,  and  found  that  the 
addition  of  some  highly  nitrogenous  feeding  stuff  to 
corn  meal,  or  other  home -raised  grain,  in  most  instances 
increased  the  productive  power  of  the  ration.  This 
fact  stands  in  apparent  conflict  with  the  more  scientific 
conclusions  to  w^hich  reference  has  been  made.  The 
probable  explanation  of  this  discrepancy  is  that  the 
rations  richest  in  protein  have  generally  contained  the 
greater  variety  of  feeding  stuffs,  have  been  more  palat- 
able, more  stimulating  to  the  appetite,  and,  in  general, 
have  caused  a  more  vigorous  exercise  of  the  animal's 
functions.  The  proportion  of  protein  has  probably 
been  a  minor  factor.  If  as  great  a  variety'  of  as  pal- 
atable and  as  easily  digestible  materials  can  be  fed 
without  the  use  of  highly  nitrogenous  feeding  stuffs 
as  with  them,  the  result  will  doubtless  be  just  as  favor- 
able. This  means  that  a  mixture  of  home-raised  grains 
m^y  form  as  efficient  a  ration  for  fairly  mature  fatten- 
ing steers  as  when  the  oil  meals  or  gluten  meals  are 
introduced.  Palatableness,  variety  and  ease  of  diges- 
tion are  the  main  points  to  be  secured,  and  these  fac- 
tors have  been  somewhat  overshadowed  by  the  effort 
to  secure  merely  a  definite  relation  of  protein  to  car- 
bohydrates. 

It  need  not  be  feared  that  when  mixed  cereal  grains 
are  fed  as  the  major  part  of  the  ration,  there  will  be 
a  materially  lower  rate  of  digestibility  than  when  a 
protein  food  is  introduced.  There  is  still  something 
to  be  said,  however,  in  favor  of  adding  to  a  fattening 
ration  a  small  proportion  of  an  oil  meal,  or  of  some 
material  of  similar  character,  for  palatableness  is  thus 


Feeding   Standard  for  Fattening   Steers         345 

promoted,  and  observations  show,  in  many  instances, 
that  an  appearance  of  greater  thrift  and  vigor  is  thus 
induced,  which  is  probably  due  to  the  stimulating  effect 
of  the  greater  amount  of  circulatory  protein  upon  the 
metabolic  processes  of  the  -animal.  With  j'oung  steers 
making  some  growth  of  bone  and  muscle,  a  small 
quantity  of  a  protein  food  is  of  unquestioned  advantage. 
The  German  standard  for  fattening  cattle  is  open 
to  criticism  as  to  the  quantity  of  nutrients  recommended 
for  1,000  lbs.  of  live  weight.  In  order  to  supply  18.4 
lbs.  of  digestible  organic  matter  it  would  be  necessary 
to  feed,  for  instance,  8  lbs.  of  hay  and  21.5  lbs.  of  an 
ordinary  mixture  of  corn  meal,  bran  and  oil  meal. 
While  it  may  be  possible  to  induce  young  steers  weigh- 
ing from  600  to  800  lbs.  to  eat  at  this  rate  for  a  short 
time,  so  large  a  ration  is  seldom,  if  ever,  so  profitable 
as  a  smaller  one,  even  if  it  could  be  fed  with  safety. 
If  an  attempt  was  made,  however,  to  apply  this  form- 
ula to  mature  steers  weighing  from  1,300  to  1,500  lbs. 
the  situation  would  become  absurd,  because  the  ration 
would  then  be  from  10.5  to  12  lbs.  of  hay  and  from 
25  to  32  lbs.  of  mixed  grains  for  a  single  animal. 
An  appeal  to  concrete  examples  of  steer  feeding  will 
clearly  show  the  excessive  requirements  of  the  German 
standard  for  fattening  cattle.  In  1891  to  1893  the 
Kansas  Agricultural  Experiment  Station  conducted 
feeding  experiments  with  three -year -old  steers,  and 
as  these  are  good  examples  of  practical  management, 
the  data  from  them  will  serve  to  illustrate  the  point 
under  discussion.  These  data  are  stated  in  a  tabular 
form : 


346  The  Feeding  of  Animals 

1st  Expt.  2d  Expt. 

Number  of  animals 5  3 

Days  fed 182  129 

Weight  per  animal,  average  for  period 1,412      lbs.  1,237     lbs. 

Hay  eaten  per  day 7.8    "  6.7   " 

Grain  eaten  per  day 23.9    "  23.     " 

Daily  gain  per  animal » 2.39"  2.4  " 

Digestible  organic  matter  daily  per  animal 19.5    "  19.     " 

Digestible  organic  matter  per  1,000  lbs.  live  weight 13.8    "  15.3  " 

In  1895-6  the  Iowa  Agricultural  College  fed  steer 
calves  for  fourteen  months,  during  ten  of  which  a 
record  was  kept  of  all  the  food  consumed.  During  the 
second  period  the  steers  were  fattened  for  market. 
This  particular  experiment  is  cited  because  the  animals 
were  young  and  all  the  conditions  were  favorable  to 
the  maximum  consumption  of  food  in  proportion  to 
live  weight: 

1st  period  2d  period 

Number  of  animals 5  5 

Days  fed. 120  181 

Age  of  steers  at  beginning 9  to  10  mos.  IG  to  17  mos. 

Weight  per  animal,  average  for  period 766  lbs.  1,197    lbs. 

Coarse  food  eaten  daily  (partly  roots  and  green  fodder).         11     "  12.8    ■" 

Grain  eaten  daily  (partly  snapped  corn) 9    "  19.5    " 

Daily  gain  per  animal 2.04  lbs.  2.11  lbs. 

Gain  per  1,000  lbs.  live  weight 2.66     "  1.76    " 

Digestible  organic  matter  daily  per  animal 10.        "  14.1 

Digestible  organic  matter  daily  per  1,000  lbs.  live  weight.        13.        "  11.8 

The  largest  amount  of  digestible  nutrients  fed  daily 
per  animal  at  any  time  during  this  experiment  was 
about  17.5  lbs.,  after  the  animals  had  reached  an 
average  weight  of  1,200  lbs.  or  over.  This  would  be 
approximately  14.5  lbs.  digestible  organic  matter  per 
1,000  pounds  live  weight. 

These  two  experiments  are  instances  of  successful 
feeding  where  the  increase  was  rapid  and  very  satis- 


Ration  for  Fattening  Steers  347 

factory,  aud  where  the  quantity  of  digestible  nutrients 
supplied  daily  was  greatly  below  18  lbs.  per  1,000  lbs. 
live  weight. 

Many  other  feeding  trials  might  be  cited  in  illus- 
tration of  the  unpractical  character  of  the  German 
standard,   when  accepted  without  modification. 

The  writer  is  led  to  conclude,  from  observation  and 
a  study  of  the  results  of  experiments,  that  under  proper 
conditions  8  to  10  lbs.  of  dry  coarse  food  and  15  to 
18  lbs.  of  grain  is  all  that  can  generally  be  fed  with 
greatest  profit  to  a  steer  actually  weighing  1,000  lbs., 
and  maj'  be  even  more  than  is  utilized  by  the  animal 
to  the  best  advantage.  Such  a  ration  would  supply 
about  16  lbs.  of  digestible  organic  matter.  If  consid- 
erably smaller  steers  are  fed  the  ratio  of  food  to  weight 
may  be  increased,  but  if  the  animals  are  several  hun- 
dred pounds  heavier  the  ratio  must  be  materially  dimin- 
ished. It  is  safe  to  accept  as  a  general  principle  the 
rule  that  the  larger  the  animal  the  less  the  proportion 
of  food  to  weight.  The  fixing  of  the  quantity  of  a 
fattening  ration  directly  in  proportion  to  the  size  of 
the  animal  is  a  simple  and  quite  convenient  rule,  but 
is  utterly  impracticable,  and  is  so  recognized  at  present 
in  the  standards  for  growing  animals  and  should  be 
in  all  estimates  and  proportions. 

THE    SELECTION    OF    A    FATTENING    RATION 

Two  conditions  already  mentioned  that  are  of  the 
highest  importance  should  not  be  forgotten;  viz.,  that 
the  ration  should  be  palatable  and  be  composed  of  a 


348  The  Feeding  of  Animals 

variety  of  easily  digestible  materials.  Rough  fodder 
in  any  quantity  is  not  adapted  to  fattening  bovioes. 
With  this  exception,  the  whole  list  of  high -class  cattle 
foods  may  be  regarded  as  available,  and  the  selection 
will  properly  depend  largely  upon  prices  and  the  local 
supply.  In  the  northern  states,  hays  from  the  fine 
grasses  and  the  legumes,  silage,  roots,  cereal  grain 
mixtures  and  such  by-product  feeding  stuffs  as  offer 
digestible  nutrients  at  the  least  cost  wdll  all  appeal  to 
the  experienced  feeder.  In  the  south,  cottonseed  by- 
products may,  with  economy,  enter  largely  into  the 
ration.  In  the  west,  the  fodders  peculiar  to  that  re- 
gion will  be  utilized,  corn  being  the  chief,  and  some- 
times the  only,  grain  that  can  be  fed  with  economy. 
The  following  may  be  regarded  as  good  types  of  mix- 
tures for  the  full  feeding  of  fattening  steers  weighing 
approximately  1,000  lbs.  each  at  the  beginning  of  the 
feeding  period.  They  will  supply  about  16  lbs.  of 
digestible  organic  matter  if  their  components  are  of 
average  quality  and  composition: 

5  lbs.  clover  hay.  [    8  lbs.  alfalfa  hay. 

16  lbs.  corn  silage.  4  J  12  lbs.  corn  meal. 
13  lbs.  corn  meal.  [    5  i^g,  ground  oats. 

3  lbs.  wheat  bran. 

10  lbs.  corn  stover.  [    5  lbs.  clover  hay. 

20  lbs.  mangels.  ^  J  r)0  lbs.  beet  pulp. 

14.5  lbs.  corn  meal.  'M  11  lbs.  corn  meal. 

2  lbs.  cottonseed  meal.  (^    2  lbs.  cottonseed  meal. 

8  Ib's.  mixed  hay.  [    8  lbs.  corn  stover. 

12.5  lbs.  corn  meal.  6  \  12.5  lbs.  corn  meal. 

3  lbs.  wlieat  bran.  [  20  lbs.  brewer's  grains,  wet. 
2  lbs.  oil  meal  or  gluten  f'd. 


Rations  for  Steers — Mutton   Production  349 

f    2  lbs.  oat  straw.  [^    5  lbs.  alfalfa  hay. 

j  75  lbs.  beet  pulp.  I    3  lbs.  corn  stover. 

I  10  lbs.  beet  molasses.  1  11  lbs.  eoru  meal. 

(^    4  lbs.  gluten  meal.  1^    G  lbs.  ground  barley. 


5  lbs.  mixed  timothy  and  clover. 
30  lbs.  silage. 

lbs.  oats  and  peas. 


^  30 

[l3 


The  above  rations  are  well  up  to  the  qnautity  limit 
for  the  profitable  feeding  of  animals  weighing  approxi- 
mately 1,000  lbs.  They  are  simply  illustrative,  how- 
ever, both  in  kind  and  in  quantity.  Many  mixtures 
equally  efficient  may  be  used,  and  the  quantity  of 
the  ration  must  vary  not  only  with  the  age  and  size 
of  the  animal  but  with  individuals,  according  to  ap- 
petite and  capacity.  Any  feeder  of  experience  will 
understand,  of  course,  that  such  rations  will  be  eaten 
with  safety  to  the  animal  only  after  a  period  of  pre- 
liminary feeding,  during  which  there  has  been  a  grad- 
ual increase  in  the  quantity  of  food  offered. 

MUTTON    PRODUCTION 

Attention  has  been  called  to  the  fact  that  beef  pro- 
duction in  the  United  States  has  gravitated  to  the 
extreme  west.  This  is  also  true  of  the  production 
of  mutton,  though  not  to  the  same  extent.  Flocks 
of  sheep  are  still  kept  on  many  farms  of  the  eastern 
and  middle -west  states,  and  the  growth  of  early  lambs 
and  the  fattening  of  maturer  animals  to  supply  the 
demands  of  the  local  markets  is  found  to  be  most 
profitable  by  those  farmers  who  possess  the  knowledge 
and  skill  Tequisite  for  this  branch  of  stock  husbandry. 


350  The  Feeding  of  Animals 

Sheep  occupy  a  peculiar  place  on  the  farm  in  that 
they  will  accommodate  themselves  to  pasturage  that 
is  not  adapted  to  cows  and  horses,  and  will  utilize 
some  kinds  of  rough  fodder  not  readily  eaten  by  other 
farm  animals  without  submitting  it  to  somewhat  ex- 
pensive methods  of  preparation.  If  it  were  not  for 
the  discouragement  which  sheep  husbandry  has  received 
from  the  depredations  of  dogs,  sometimes  real  and 
sometimes  greatly  overestimated  or  even  imagined, 
the  production  of  wool  and  mutton  would  greatly  in- 
crease on  the  hill  farms  of  this  country,  with  undoubted 
profit  to  eastern  agriculture  especially,  where  soil  fer- 
tility needs  strengthening  in  every  possible  way. 

THE  NATURE  AND  EXTENT  OF  THE  GROWTH  IN  FAT- 
TENING SHEEP 

The  character  of  the  animal  that  is  fattened  for 
mutton  varies  within  wider  extremes  than  in  steer 
feeding.  This  is  due  chiefly  to  the  greater  range  in 
maturity  of  the  former,  from  the  two  months'  lamb  to 
the  mature  wether.  There  are  corresponding  differences 
in  the  nature  of  the  increase  while  fattening,  accord- 
ing as  the  animal  is  3'oung  and  making  growth  of  all 
parts  of  the  body  or  is  simply  storing  fat  in  the  mature 
organism.  The  character  of  the  body  substance  stored 
probably  is  also  influenced  by  the  stage  in  the  fatten- 
ing period,  whether  at  the  beginning  when  the  animal 
is  thin'  or  near  the  end  when  a  fat  sheep  is  becoming 
fatter.  The  only  deflnite  data  which  can  be  presented 
relative  to  the  composition  of  the  increase  of  fattening 


Character  of  Increase  of  Fattening  Sheej)        351 

sheep  are  based  upon  the  analyses  by  Lawes  &  Gilbert 
of  animals  in  various  states  of  fatness.  These  inves- 
tigators analyzed  a  "store"  sheep,  a  "fat"  sheep  and  a 
"very  fat"  sheep,  and  from  the  figures  thus  obtained 
are  calculated  the  increase  in  two  stages  of  fattening: 

Composition  of  increase  of  fattening  slieep 

substance  Ash    Protein    Fat 

%  %           %          % 

Increase  from  "store"  to  "fat"  condition.  78.  2.12    7.16    68.8 

Increase  from  "fat"  to  "very  fat"  condition. 81. 8  3.12     7.75     70.9 

A  comparison  with  the  increase  of  fattening  oxen 
shows  that  the  sheep  stores  the  larger  proportion  of 
fat  in  the  dry  substance  laid  on. 

Sheep  liberally  fed  give  a  larger  increase  per  1,000 
lbs.  live  weight  than  steers.  With  animals  weighing 
from  75  to  150  lbs.  each  the  daily  gain  with  good 
management  may  range  from  .2  to  .5  lb.  per  head, 
or  from  2  to  5  lbs.  per  1,000  lbs.,  live  weight,  the 
increase  varying  according  to  age,  conditions  and  lib- 
erality of  feeding.  Lambs  will  sometimes  greatly  ex- 
ceed the  above  maximum.  If  we  base  our  estimates 
upon  what  will  occur  with  the  maturer  animals,  a  num- 
ber of  lambs  or  sheep  weighing  1,000  lbs.,  perhaps 
seven,  perhaps  twice  as  many,  will  store  daily  .15  to 
.40  lb.  of  protein  and  from  1.4  to  3.5  lbs.  of  fat. 

FOOD  NEEDS  OF  FATTENING  SHEEP 

After  long -continued  and  careful  experiments  in 
feeding  a  fattening  ration  to  mature  sheep,  whose 
composition    was    investigated    at    various     stages    of 


352  The  Feeding  of  Animals 

fatness,  Henueberg  concludes  that  the  very  small 
amount  of  muscle  tissue  laid  on  by  such  animals  may 
"be  ignored.  Pfeiffer  reached  the  same  conclusion  from 
experiments  with  the  same  class  of  animals.  This 
view  would  not  hold  with  lambs  during  their  increase 
from  weaning  time  to  100  lbs.  in  weight,  for  in  this 
period  there  must  be  a  material  and  continuous  storage 
of  nitrogenous  tissue. 

As  is  the  case  with  steers,  the  demand  for  protein 
storage  is  seen  to  be  small  with  mature  fattening  sheep, 
the  constructive  use  of  the  ration  being  largely  directed 
to  fat  formation.  The  more  recent  views  of  the  func- 
tion of  the  nutrients  allow  us  to  believe  that,  as  with 
bovines,  carbohydrates  and  perhaps  fats  play  a  leading 
part  in  supplying  raw  materials  for  the  carcass  increase. 
There  is  one  point  of  difference  between  steers  and 
sheep,  however:  viz.,  the  growth  of  wool  with  the  lat- 
ter, that  requires  the  use  of  more  or  less  food  protein. 

The  German  standard  for  fattening  sheep  is  18.5 
to  18.6  lbs.  of  total  digestible  organic  matter  per  1,000 
lbs.  live  weight,  3  to  3.5  lbs.  of  which  shall  be  protein, 
thus  giving  a  nutritive  ratio  ranging  from  1:4.5  to 
1:5.4.  There  is  little  doubt  that  this  standard  calls  for 
an  unnecessarily  large  proportion  of  protein.  Neither 
scientific  facts  nor  the  observations  of  practice  justify 
the  conclusion  that  sheep  will  fatten  faster  when  pro- 
tein is  so  liberally  supplied  than  when  properly  com- 
pounded rations  with  a  wider  nutritive  ratio  are  fed. 
Doubtless  more  regard  should  be  paid  to  the  protein 
supply  with  sheep  than  with  steers,  but  it  is  difficult 
to    adduce    a    single    argument    for    insisting   upon    so 


Feeding  Standards  for  Fattening  Sheep         353 

narrow  a  nutritive  ratio  with  any  species  of  fattening 
animal,  unless  it  becomes  incidental  to  an  economfcal 
purchase  of  feeding  stuffs.  We  may  safely  conclude 
that  the  resources  of  the  farm  are  sufficient  to  supply 
enough  protein  for  a  ration  of  an  efficient  character 
for  the  class  of  animals  under  consideration,  thongh 
we  should  give  due  recognition  to  the  fact  that,  with 
fattening  lambs  especially,  the  protein  feeding  stuffs 
may  be  most  efficiently  utilized. 

The  quantity  of  nutrients  prescribed  by  the  pub- 
lished standard  for  fattening  is  practically  the  same 
per  unit  of  weight  as  that  given  for  fattening  bovines. 
This  runs  contrary  to  common  observation  and  the 
results  of  experiments.  The  standard  for  steers  has 
been  characterized  as  excessive,  but  this  fault  cannot 
be  charged  to  the  one  for  sheep,  for,  if  anything,  it  is 
below  the  demands  of  practice.  Even  mature  sheep  about 
average  size  will  consume  18.5  lbs.  of  digestible  nutri- 
ents per  1,000  lbs.  live  weight,  but  this  ratio  does  not 
meet  the  requirements  for  the  prevalent  intensive  feed- 
ing of  lambs  and  yearlings  weighing  from  75  to  125 
lbs.  each.  It  is  easily  demonstrable  not  only  that  sheep 
will  utilize  a  proportionately  larger  quantity  of  food 
than  bovines,  but  that  they  will  make  a  relatively 
greater  increase.  The  results  of  two  experiments  in 
fattening  wether  lambs,  reported  from  the  Iowa  Agri- 
cultural College  in  1896  and  1897,  when  compared  with 
the  outcome  of  steer -feeding  trials,  serve  admirably  to 
illustrate  the  correctness  of  this  statement.  The  lambs 
were  divided  among  seven  mutton  breeds.  Sixty -nine 
were  fed  90  days  and  64  others  were  fed  107  days. 

w 


354  The  Feeding  of  Animals 

The  main  facts  derived  from  these  feeding  trials 
aiT  as  follows: 

Number  of  animals    133 

Average  days  fed 98.2 

Total  average  weight  of  animals  16,400  lbs. 

Average  weight  single  animal 123     ' ' 

Dry  matter  consumed 51,000     ** 

Digestible  organic  matter  consumed 34,500     " 

Dry  matter  eaten  daily  per  1,000  lbs.  live  wt.  .  .        31.8  *' 
Digestible  organic  matter  eaten  daily  per  1,000 

lbs.  live  weight 21.5  " 

Daily  gain  per  1,000  lbs.  live  weight 3.73  lbs. 

Daily  gain  per  animal .467    ' ' 

The  food  consumption  in  this  instance  of  the  suc- 
cessful fattening  of  lambs  is  considerably  in  excess  of 
the  German  standard;  and  the  amount  of  food  con- 
sumed is  not  unusual,  though  it  is  stated  that  in  the 
latter  stages  of  the  experiments  the  animals  were 
crowded  to  their  full  capacity. 

If  a  comparison  is  made  of  this  experiment  with 
the  steer  feeding  experiments  previously  cited  it  be- 
comes clearly  evident  that  the  published  feeding  stand- 
ards are  not  consistent  in  calling  for  practically  the 
same  quantity  of  nutrients  for  the  same  live  weight 
of  the  two  species.  Sheep  will  consume  at  least  one- 
quarter  more  food  than  steers  and  lay  on  Hesli  propor- 
tionately faster.  Moreover,  sheep  appear  to  make  a 
larger  gain  in  live  weight  than  steers  for  each  unit  of 
nutrients  consumed.  It  may  be  that  the  testimonj-  of 
the  experiments  cited  relative  to  the  points  under 
discussion  is  not  a  correct  expression  of  the  average 
conditions,  but  the   differences   shown  are  too   marked 


Rations  for  Fattening  Sheep  355 

to  be  accounted  for  b}'  any  unusual  conditions  pertain- 
ing to  these  feeding  trials,  and  therefore  indicate  what 
may  generally  be  expected  in  practice. 

THE  SELECTION  OF  A  RATION  FOR  SHEEP 

The  range  of  feeding  stuffs  from  which  a  sheep 
ration  may  be  selected  is  wide  and  includes  practically 
all  home -raised  fodders  and  grains  and  the  whole  list 
of  by-products.  It  cannot  be  said,  though,  that  all 
materials  are  equally  desirable  as  sheep  food.  Of  the 
fodders,  those  from  the  legumes  are  especially  to  be 
sought,  even  pea  and  bean  straws,  and  among  the 
grains  corn  stands  preeminent  as  the  basis  of  a  fat- 
tening ration.  Probably  no  feeding  stuffs  are  more 
favored  for  mixing  with  corn  than  oats,  bran  and 
linseed  meal,  probably  because  none  are  more  success- 
fully used.  Barley,  peas,  beans,  gluten  feed,  gluten 
meal  and  cottonseed -meal  have  also  been  successfully 
fed  to  sheep.  A  mixed  grain  ration  is  unquestionably 
to  be  preferred  to  any  single  grain  or  by-product,  be- 
cause with  the  mixture  greater  palatableness  is  insured, 
it  is  possible  to  maintain  the  consumption  of  a  larger 
ration,  and  the  danger  to  health  of  heavy  feeding  is 
less.  The  selection  of  the  components  of  the  grain  mix- 
ture should  be  governed  somewhat  by  market  prices. 
A  supply  of  silage  or  roots  is  much  to  be  desired  as 
a  part  of  a  sheep  -  fattening  ration,  especially  when 
heavy  grain  rations  are  to  be  fed  during  a  long  period, 
although  successful  feeding  during  a  limited  time  is 
entirely   possible    without    these.       A    succulent    food 


356  The  Feeding  of  Anwials 

promotes  appetite  and  health,  however,  and  is  usually 
economical   and  sometimes  necessary. 

Rations  made  up  in  definite  quantities  will  not  be 
presented  in  this  connection.  The  quantity  of  nutri- 
ents which  it  is  desirable  to  supply  is  so  variable 
according-  to  the  age  and  maturity  of  the  animals  to 
be  fattened  that  a  feeding  standard  is  applicable  to 
only  one  set  of  conditions  not  long  maintained  and 
therefore  it  must  be  freely  and  frequently  modified 
according  to  the  judgment  of  the  feeder.  It  is,  nev- 
ertheless, possible  to  offer  practical  suggestion  as  to 
the  proportions  of  grains  in  the  mixtures  that  will  be 
found  acceptable  and  as  to  the  kinds  and  quantities 
of  coarse  foods  ordinarily  utilized. 

In  the  Iowa  experiments  cited  in  this  connection 
the  grains  used  were  corn,  oats,  bran  and  linseed  meal. 
In  the  last  of  these  trials  the  grain  ration  for  fifteen 
daj^s  at  first  was  made  up  of  corn,  oats  and  bran  in 
the  proportions  2,  2  and  1.  When  the  feeding-  was 
well  established  the  grains  were  oats,  corn,  bran  and 
oil  meal,  the  relation  in  quantity  being  8,  8,  2  and  1 
respectively.  Each  animal  ate  about  1  pound  of  roots 
daily  and  about  two -thirds  as  much  hay  as  grain. 
The  lambs  were  fed  up  to  the  full  ration  very  grad- 
ually, several  weeks  being  occupied  in  doing  this.  For 
such  preparatory  feeding  bran  and  oats  are  especially 
useful.  When  these  tests  began,  each  animal  ate  from 
one  and  a  half  to  two  pounds  of  grain  daily,  which 
quantity  was  increased  later  to  three  pounds  with  the 
largest  eaters,  some  individuals  not  taking  over  two. 
The  conduct  of  these  feeding  trials  typifies  good  prac- 


Foods  for  Fattening   Slieep  —  Feeding   Stvine     357 

tice,  both  as  to  materials  aud  management,  and  maj' 
serve  as  a  guide  in  handling  other  similar  feeding  stuffs. 

It  is  undoubtedly  possible  to  feed  sheep  with  equal 
success  without  the  use  of  purchased  grains,  especially 
on  farms  where  clover  or  alfalfa,  roots,  corn,  oats,  or 
oats  and  peas  are  produced.  We  are  not  justified  by 
experimental  results  in  concluding  that  bran  and  oil 
meal  or  any  other  by-product  feeds  are  essential  to 
the  highest  success  in  fattening  sheep,  although  these 
feeding  stuffs  are  very  useful  for  this  purpose.  A 
mixed  grain  ration  is  always  better  than  any  single 
grain  fed  alone. 

Instances  are  on  record  of  a  successful  combination 
of  green  forage  crops  with  grain  in  fattening  sheep. 
The  legume  fodders  and  rape  may  be  fed  profitably  in 
the  green  state  with  the  usual  grain  mixtures,  care 
being  taken  to  avoid  indigestion  from  excessive  eating 
of  the  green  material. 

Grain  in  connection  with  ordinary  pasturage  is  a 
successful  method  of  fattening  sheep  or  lambs  for  the 
fall  market. 

PORK    PRODUCTION 

The  feeding  of  swine  is  a  matter  of  almost  univer- 
sal interest  to  farmers.  Even  in  the  older  portions 
of  the  east  a  few  animals  of  this  class  are  kept  on 
nearly  every  farm.  Swine  are  well  adapted  to  the  dis- 
posal of  certain  wastes,  particularly  those  from  the 
table  and  the  dairy.  They  are  especially  useful  as  a 
means  of  profitably  converting  dairy  by-products  into 
a   marketable   form,    and,    moreover,    during   the   past 


358  The  Feeding  of  Animals 

twenty -five  years  pork  prodactioii  has  offered  more 
encouraging  inducements  to  the  home  consumx^tion  of 
grain  than  has  beef  production. 

Within  recent  years  there  has  been  a  great  change 
in  the  methods  of  pig  feeding  and  in  the  character  of 
the  animal  when  placed  upon  the  market.  This  is 
emphatically  true  of  the  eastern  and  middle  states, 
where  pork  is  grown  wholly  for  local  consumption. 
Formerly  good  feeders  were  not  supposed  to  slaughter 
a  pig  under  three  hundred  pounds  carcass  weight, 
and  many  animals  dressed  four  hundred  pounds  when 
taken  to  the  market,  this  size  being  secured  only  after 
a  feeding  period  of  twelve  to  eighteen  months.  Pork 
of  this  character  was  regarded  as  well  adapted  to  pack- 
ing. At  the  present  time  the  demand  of  the  local 
markets  is  for  small  carcasses  weighing  not  over  one 
hundred  and  fifty  pounds,  and  supplying  the  maxi- 
mum proportion  of  lean  cuts.  This  change  is  in  the 
direction  of  greater  profits  for  the  farmer,  as  he  has 
learned,  because  the  food  expenditure  required  for  the 
production  of  small  carcasses  is  much  less  per  unit  of 
weight  than  under  the  old  system,  when  the  feeding 
was  continued  during  a  longer  period.  Pigs  properlj^ 
fed  are  now  wisely  turned  off  at  the  age  of  a  few 
months,  excepting,  perhaps,  in  those  localities  where  a 
slow  early  growth  is  cheaply  secured  on  pasturage. 

CHARACTER  OF  THE  GROW^TH  IN  PORK  PRODUCTION 

The  modern  hog  is  empliatically  a  fat -producing 
organism,  having  a  capacity  in  this  particular   greatly 


Character  of  Growth   with   Pigs  359 

surpassiug  any  other  species  of  domestic  animal.  The 
dry  matter  of  the  carcasses  of  individual  animals  has 
been  found  to  consist  of  over  80  per  cent  of  fat,  even 
after  the  leaf -lard  was  removed,  and  the  average  pro- 
portion in  the  dry  substance  of  eight  dressed  pigs,  rep- 
resenting six  breeds,  was  found  by  Wiley  to  be  78  per 
cent. 

The  statement  of  the  composition  of  a  Berkshire 
pig  and  of  a  Duroe- Jersey  will  be  found  interesting  in 
this  connection  : 

Composition   of  the  entire  dressed  animal,   head,   leaf-lard  and 
Jcidneys  removed.      Wiley. 


Weight 
carcass 

Water 

Dry 
substance 

Ash 

Protein 

Fat 

% 

% 

% 

% 

% 

% 

129 

43.1 

56.9 

2.6 

13. 

40.5 

'sev.  . . 

149 

30.  G 

C9.4 

1.8 

9. 

57.7 

Fat  pig,  entire  animal 

(Lawes  &  Gilbert)..  43.9         56.1         1.9         11.9       42.3 

It  appears  that  there  was  stored  in  the  part  of  the 
animal  analyzed  by  Wiley  only  13  pounds  of  protein 
with  the  Duroc- Jersey  and  about  17  pounds  with  the 
Berkshire,  the  quantities  of  fat  being  52  pounds  and 
86  pounds,  respectively.  The  figures  for  the  entire 
animal,  as  analyzed  by  Lawes  and  Gilbert,  are  at  the 
rate  of  23.8  pounds  protein  and  84.6  pounds  fat,  in  a 
pig  weighing  200  pounds. 

These  proportions  bring  out  sharply  the  character 
of  the  growth  with  swine.  It  is  to  be  noted  that  in 
no  other  species,  very  fat  sheep  possibly  excepted, 
does  the  body  consist  so  largely  of  dry  matter,  which 
means  that   the   increase  of  a  unit  of   live  weight    in- 


360  The  Feeding  of  Animals 

volves  the  storage  of  more  food  substance  than  with 
other  domestic  animals.  The  data  at  our  command 
warrant  the  statement,  in  a  general  way,  that  when  a 
pig  gains  1.5  lbs.  daily  in  live  weight  he  stores  not 
less  than  .84  lb.  of  dry  substance,  of  which  .18  lb. 
is  protein  and  .63  lb.  is  fat,  these  figures  representing 
the  average  growth  during  the  life  of   the  animal. 

Lawes  and  Gilbert  estimate  that  the  increase  of  pigs 
while  fattening  has  the  following  composition: 

Water    Dry  substance        Ash  Protein  Fat 

22%  78%  .10%  6.4%  71.5% 

According  to  these  figures  the  protein  storage,  with 
1.5  lbs.  daily  gain,  would  be  only  .10  lb.  and  the  fat 
1.07  lbs. 

FOOD  REQUIREMENTS  FOR  PORK  PRODUCTION 

Feeding  the  r/r/>;?.  —  Under  a  system  of  intensive 
production  pigs  go  to  market  so  young  that  we  may 
properly  discuss  their  feeding  from  birth.  We  deal 
first  with  the  mother  as  a  milch  animal.  According 
to  observations  by  Henry,  in  an  inquiry  as  to  the 
yield  and  composition  of  sow's  milk,  it  seems  probable 
that  in  proportion  to  their  weight  small  sows  yield  as 
large  a  quantity  of  milk  solids  dailj^  as  a  good  cow. 
The  average  daily  production  of  milk  solids  per  animal 
appeared  to  be  about  one  pound.  This  would  be  four 
pounds  for  four  sows,  which  is  the  equivalent  of  the 
solids  in  over  thirty  ]iounds  of  cow's  milk  of  average 
quality.     It  follows,  therefore,  that  the  demands  upon 


Food  Requirements  of  Pigs  3G1 

the  food  for  milk  formation  are  proportionally  as  lieavj- 
with  swine  as  with  cows,  and  conseqnenth'  the  ration 
should  be  one  that  will  stimulate  and  sustain  abundant 
milk  secretion.  Such  feeding  is  not  only  necessary, 
but  economical,  for  independent  experiments  indicate 
that  the  food  cost  of  the  growth  of  pigs  before  wean- 
ing is  no  greater  than  it  is  after  weaning. 

Skimmed  milk  or  buttermilk  combined  with  a  mix- 
ture of  wheat  middlings  and  one  of  the  ground  cereal 
grains,  barley,  oats  or  corn,  cannot  be  improved  upon 
as  food  for  milch  sows.  The  feeding  should  be  liberal, 
quite  up  to  the  limits  of  capacity,  and  even  then  the 
dam  suckling  a  large  litter  of  young  will  grow  thin. 

Feeding  j)hj^  for  tlie  marJi'et. —  If  w^e  merely  consider 
the  nature  of  the  body  substance  of  swine  in  its  rela- 
tion to  the  constructive  functions  of  the  nutrients,  it 
would  not  be  unreasonable  to  believe  that  rations  with 
a  wide  nutritive  ratio  are  adapted  to  the  needs  of  this 
class  of  animals  for  growth.  In  a  certain  sense,  prac- 
tice ratifies  this  view.  Thousands  of  fat  hogs  have  been 
the  product  of  almost  exclusive  corn  feeding,  especially 
during  the  later  stages  of  growth.  There  is  no  doubt 
but  that  large  size  and  an  excessively  fat  condition 
may  be  secured  through  a  liberal  supply  of  carbohy- 
drate material,  but  such  one-sided  nutrition  is  not 
now  regarded  as  being  adapted  to  the  physiological 
requirements  of  the  pig  or  as  producing  pork  Avhich 
meets  the  existing  demands  of  the  market. 

It  is  doubtful  if  auy  other  species  of  domestic  ani- 
mal has  been  the  subject  of  so  much  abuse  through 
improper   feeding,    combined  with    an   unhealthful    en- 


362  The  Fcfding  of  Animals 

viroument,  as  has  the  pig.  We  now  regard  the 
abnormal  masses  of  porcine  fat  which  have  heretofore 
appeared  in  our  markets  as  not  only  an  exhibition  of 
physical  monstrosities,  but  as  not  serving  the  health 
interests  of  the  human  family. 

The  primary  object  in  feeding  pigs  should  be,  as 
with  all  domestic  animals,  the  securing  of  a  normal 
and  vigorous  physiological  development,  i.  e.,  an  or- 
ganism with  a  strong  bony  structure  and  with  such  a 
growth  of  muscular  tissue  as  shall  insure  full  exercise 
of  all  the  vital  functions.  The  view  seems  to  have 
prevailed,  in  a  practical  way  at  least,  that  pigs  can  be 
fed  on  anything,  live  and  sleep  anywhere  and  still  not 
suffer  ill  effects,  as  would  be  the  case  with  the  other 
farm  animals.  This  has  been  unfortunate,  because 
probably  no  other  domestic  species  is  so  susceptible  to 
abnormal  development  through  improper  feeding  as 
are  swine.  It  is  true,  at  least,  that  no  other  species 
has  shown  so  marked  a  response  to  changes  in  the 
character  of  the  rations,  through  modifications  of  the 
bony  structure  and  through  variations  in  the  propor- 
tions of  muscle  and  fat  tissue. 

Notable  proof  of  the  plasticity  of  the  pig's  organ- 
ism was  supplied  by  the  experiments  of  Sanborn  and 
Henr}^  in  comparing  rations  extremely  nitrogenous  with 
those  extremely  carbohydrate  in  character.  Pigs  fed 
liberally  on  blood,  milk  and  shorts  combined  with 
more  or  less  corn  meal,  made  growth  more  rapidly, 
had  stronger  bones,  larger  organs  and  more  muscular 
tissue  than  those  fed  on  corn  meal  or  a  mixture  of 
corn  meal  with  other  highlj'  non-nitrogenous  materials, 


Food  Requivpynents  of  Pigs  363 

such  as  potatoes  and  tallow.  The  latter  combination 
was  deficient  both  in  protein  and  in  bone -forming 
compounds.  Such  marked  differences  are  not  usually 
seen,  because  rations  are  not  generallj'  so  extremely 
one-sided.  These  experiments  teach  the  lesson,  though, 
that  as  much  care  should  be  exercised  in  choosing  the 
pig's  ration  as  the  cow's. 

Experimental  observations  demonstrate  that  the 
pig's  ration  should  be  selected  with  reference  to  sup- 
plying an  abundance  of  bone -making  material  and  a 
reasonably  large  proportion  of  protein.  Evidence  is 
not  wanting  that  the  feeding  of  wood  ashes  and  ground 
bone  to  growing  pigs  promotes  both  a  normal  develop- 
ment of  the  bony  framework  and  a  more  liberal  con- 
sumption of  food.  Animals  that  are  grazing  may  not 
need  to  have  the  ration  so  supplemented,  but  it  is 
wise  and  even  necessary  with  those  confined  in  pens. 

In  selecting  foods  for  the  production  of  small  pork 
where  the  development  of  all  forms  of  tissue  is  taking- 
place,  first  rank  must  be  given  to  the  dairy  wastes. 
As  a  means  of  promoting  rapid  growth  and  a  condi- 
tion of  health  and  vigor,  and  also  as  a  supplement  to 
cereal  grain  products,  skim -milk  and  buttermilk  are 
not  excelled,  and  perhaps  not  equaled,  by  m\y  other 
feeding  stuffs.  In  order  to  secure  the  maximum  result 
from  a  given  quantity  of  dairy  wastes,  they  should  be 
fed  in  combination  with  grain  products.  When  this 
is  done,  and  the  i)roportions  of  skim -milk  or  butter- 
milk and  grain  are  what  they  should  be,  it  appears  to 
require  less  digestible  food  substance  for  a  pound  of 
growth    than    when    grain    is    ff»^^    «^lone    or    when    the 


364  The  Feeding  of  Animals 

liquid  food  is  largely  eaten.  In  other  words,  dairy 
wastes  are  not  o\\\y  efficient  in  themselves  in  producing 
growth,  but  in  proper  combination  they  cause  a  saving 
of  the  grain  products  necessary  to  secure  a  given  ratio 
of  gain.  Henry  states,  on  the  basis  of  eight  feeding 
trials  involving  the  use  of  ninety  pigs,  that  462  lbs. 
of  skimmed  milk  effected  a  saving  of  100  lbs.  of  corn 
meal.  This  means  that  46.2  lbs.  of  digestible  milk 
solids,  when  combined  with  corn  meal,  saved,  approxi- 
mately, 76  lbs.  of  digestible  corn  meal  substance. 

Henry's  experiments  were  arranged  so  as  to  gain 
information  as  to  the  most  desirable  proportion  of 
milk  and  meal,  and  from  his  data  the  writer  has  cal- 
culated the  quantity  of  digestible  nutrients  required  in 
each  combination  for  one  pound  of   growth: 

Digestible  matter  required 
for  1  lb.  of  gain 
Combination  lbs. 

Mixed  grains  alone      3.9 

1  lb.  corn  meal  to  1-3  lbs.  skim-milk 3. 

1    ''  "  "  3-5    '*  "  3.1 

1    "  "  ''  5-7    "  "  3.3 

1    "  "  "  7-9    "  "  3.2 

These  results  show  the  greatest  food  efficiency  with 
the  minimum  proportion  of  skim -milk.  Other  experi- 
ments, notably  those  by  Linfield  and  Robertson,  give 
similar  testimony.  With  the  former,  in  seven  experi- 
ments, a  milk  and  grain  ration  produced  1  lb.  of  gain 
for  each  2.58  lbs.  of  digestible  matter,  the  requirement 
with  milk  alone  being  2.85  lbs.  and  with  grain  alone 
3.19  lbs.  When  2  lbs.  of  skim -milk  was  fed  with 
1  lb.  of  grain,   100  lbs.  of   the  milk   replaced    31    lbs. 


Food  Adapted  to  Pigs  365 

of  gmin,  but  when  the  milk  and  grain  were  as  ^  to 
1,  100  lbs.  of  milk  only  i-eplaced  24  lbs.  of  grain. 

Doubtless  with  pigs  in  the  earliest  stages  of  growth 
after  weaning,  the  proportion  of  milk  to  grain  may 
well  be  larger  than  in  the  more  mature  periods,  and 
in  any  case  the  ratio  will  naturally  depend  somewhat 
on  the  relative   supply  of  the  milk  and  grains. 

In  the  absence  of  dairy  wastes,  meat  meal,  dried 
blood  and  fish  scraps  may  be  used  to  supplement  the 
grain  products  or  a  mixture  of  the  more  nitrogenous 
feeding  stuffs  with  corn  and  barley  will  be  found  greatly 
superior  to  the  corn  or  barlej'  alone.  Milk  is  more 
efficient  with  j'oung  pigs  than  the  grain  feeds  rich  in 
protein,  but  in  the  maturer  periods  the  digestible  mat- 
ter of  certain  of  the  latter  seems  to  have  a  value  not 
greatly,  if  any,  below  that  of  skim -milk  solids. 

The  protein  feeds  adapted  to  pigs  are  gluten  meal, 
gluten  feed,  buckwheat  middlings,  brewer's  waste, 
peas  and  middlings.  The  oil  meals,  excepting  in  small 
quantities,  affect  the  health  of  swine  unfavorably,  and 
wheat  bran  is  inferior  to  middlings. 

Of  the  carbohydrate  foods,  oats,  barley,  wheat, 
rice  products,  and  especially  corn,  are  all  useful. 
Although  the  excessive  corn  feeding  of  swine  is  to  be 
deplored,  this  grain  is  second  in  value  to  no  other 
in  the  pig's  ration,  and  only  needs  to  be  reinforced 
with  more  nitrogenous  feeds  in  order  to  find  a  safe 
and  profitable  use.  In  the  later  stages  of  growth  or 
fattening  it  may  well  form  the  major  part  of  the 
ration.  Probably  no  combination  has  been  found 
more   satisfactory  for  all  around  use   than   skim -milk, 


366  The  Feeding  of  Animals 

wheat  iniddliiigs  and  corn  meal,  the  latter  constituting 
the  larger  proportion  of  the  grain  food. 

At  the  present  time  mach  attention  is  given  to 
forage  crops  for  swine.  Clover,  alfalfa,  rape,  sor- 
ghum, rye  and  ordinary  pasturage  have  all  been  found 
to  be  adapted  to  hogs.  When  fed  with  grain,  eco- 
nomical and  satisfactory  production  is  secured.  When 
fed  alone  the  growth  is  so  slow  as  to  be  unsatis- 
factory. In  two  experiments  at  the  Wisconsin  Ex- 
periment Station,  one  acre  of  rape,  when  combined 
with  grain,  proved  to  be  equal  to  2,767  lbs.  of  corn 
and  shorts.  Other  observations  show  beyond  question 
that  such  feeding  is  practicable  and  under  some  con- 
ditions profitable.  Better  results  seem  to  follow  when 
the  pigs  are  allowed  to  graze  than  when  the  fodder 
crop  is  cut  and  fed  to  animals  confined  in  pens. 


CHAPTER    XXIV 

FEEDING    WORKING    ANIMALS 

The  working  auimals  now  iu  use  iu  the  United 
States  are  chiefly  horses  and  mules.  Oxen  were  once 
emploj'ed  extensively  for  farm  labor  and  in  lumbering, 
but  these  are  rarely  seen  under  the  yoke  at  the  pres- 
ent time,  except  in  remote  rural  districts.  It  will  be 
proper,  therefore,  to  treat  in  this  connection  chiefly  of 
horses  that  are  used  for  draft  and  road  purposes. 

The  horse  a  machine. — In  feeding  a  working  animal 
the  essential  product  of  the  food  is  energy  to  be  used 
in  drawing,  walking  or  trotting.  The  latent  food  en- 
ergy is  made  available,  as  heretofore  stated,  by  the 
oxidation  of  the  several  nutrients  into  the  ordinary 
products  of  combustion,  and  the  units  of  heat  or  work 
or  other  forms  of  kinetic  energy  evolved  are  directly 
proportional  to  the  quantity  of  digested  food  which 
suffers  combustion,  just  as  the  possible  work  of  a 
steam  engine  under  given  conditions  is  proportional 
to  the  fuel  consumption  in  the  boiler.  The  establish- 
ment of  fundamental  relations  between  food  and  work 
requires  on  the  one  hand  an  understanding  of  the 
energy  values  of  food,  and  on  the  other  hand  at  least 
a  general  conception  of  the  amount  of  work  performed. 
The  energy  values  of  food  have  been  considered  and 

(3(37) 


368  The  Feeding  of  Animals 

it  now  remains  for  us  to  ascertain  what  is  known  con- 
cerning energy  consumption  by  a  laboring  animal. 

The  ivork  performed  by  a  liorse. — The  labor  per- 
formed by  a  draft  or  road  animal,  exclusive  of  the 
energy  required  for  maintenance,  may  be  regarded  as 
consisting  of  two  components;  viz.,  the  effort  of  mov- 
ing the  load  and  that  of  moving  the  animal's  body. 
If  a  horse  weighing  1,000  lbs.  draws  one  mile  a  wagon 
which,  with  its  load,  weighs  1,500  lbs.,  2,500  lbs.  of 
matter  have  been  moved  through  the  distance  traveled. 
In  other  words,  a  horse  moves  himself  and  his  load, 
whether  the  load  is  drawn  on  a  wagon  or  is  loaded  on 
his  back. 

The  exact  expenditure  of  energy  involved  in  both 
of  these  components  cannot  be  measured  directly.  The 
work  of  drawing  a  load  may  be  determined  by  the  use 
of  a  dynamometer,  but  it  can  only  be  estimated  so  far 
as  the  body  of  the  horse  is  concerned.  If  the  latter 
factor  could  be  calculated  on  the  basis  of  simply,  pro- 
jecting a  mass  of  matter  through  tlie  space  traveled 
it  would  be  a  comparatively  simple-  problem.  There  is 
a  vertical  motion  of  the  horse's  body  to  be  accounted 
for,  as  well  as  a  horizontal,  and  the  reduction  of  both 
to  units  of  work  is  a  difficult  matter.  If  this  could 
be  done,  our  present  knowledge  of  tbe  food  energy 
necessary  for  the  performance  of  a  unit  of  mechani- 
cal labor  would  allow  quite  definite  calculations  of  the 
daily  food  needs  of  horses  of  different  classes.  As  a 
matter  of  fact,  the  actual  work  accomplished  by  labor- 
ing animals  lias  been  to  quite  an  extent  a  matter 
of   estimation,  and    still    is. 


Energy   Expenditure  hy  Horses  369 

Chardin,  a  French  army  veteriiiariao,  estimates  thnl 
the  average  daily  work  performed  is  about  2,580  foot 
tons.  Lavakird  caleuhites  that  the  total  ordinary  work 
of  an  army  horse  equals  8,500  foot  tons.  As  stated 
by  Armsby,  the  ordinary  day's  work  of  a  horse  is 
estimated  at  1,500,000  kilogram  meters,  or  5,425  foot 
tons,  this  evidently  meaning  the  mechanical  labor  out- 
side the  motion  of  the  body.  With  the  knowledge  we 
now  possess  it  is  possible  to  estimate  approximately 
the  actual  work  performed  in  a  given  case. 

It  would  be  a  good  day's  labor  if  a  1,000 -lb.  horse 
travels  twenty  miles  over  a  smooth,  level,  dirt  road 
hauling  a  wagon  with  a  load  of  2,000  lbs.  Tlie  draft 
of  the  loaded  wagon  would  be  not  far  from  100  lbs. 
A  simple  calculation  shows  that  the  mere  moving  of 
such  a  load  the  distance  of  one  mile  would  be  equiva- 
lent to  264  foot  tons.  The  energy  expenditure  in 
walking  a  given  distance  has  been  measured  by  Zuntz, 
who  ascertained  the  difference  in  oxygen  consumption 
of  a  horse  when  at  rest  and  when  traveling  at  a 
walk  over  a  level  road.  According  to  these  meas- 
urements, it  appears  that  a  1,000-lb.  horse  in  walking 
one  mile  at  the  rate  of  two  to  three  miles  per  hour 
would  expend  a  total  energy  of  473  foot  tons,  44.4 
per  cent  or  201  foot  tons  of  w4iich  belong  to  the 
effort  of  walking  over  and  above  the  energy  needed  for 
mere  maintenance.  In  the  case  assumed,  a  horse  would 
perform  a  total  labor  in  walking  and  drawing  twenty 
miles  equivalent  to  lifting  9,300  tons  through  a  space 
of  one  foot.  This  estimate  is  presented  merely  as  an 
approximation  of  the  work  done  under  given  conditions. 


870  The  Feeding  of  Animals 

These  figures  are,  perhaps,  less  important  to  the 
owner  of  work  or  driviDg"  horses  than  is  a  knowledge 
of  the  influence  of  speed  upon  the  labor  expended  in 
a  unit  of  time.  "According  to  Marcey,  the  work 
accomplished  in  a  given  time  is  proportionate  to  the 
square  of  the  velocity.  His  coefficients  were  3.42  for 
walking  or  pacing,  16  for  trotting,  28. G2  for  canter- 
ing, and  G8.39  for  a  full  gallop."  This  general  fact 
would  be  applicable  to  horses  under  all  conditions  of 
labor.  Moreover,  it  is  clearly  demonstrated  by  two  in- 
vestigators that  the  food  energy  required  for  a  unit  of 
work  increases  with  the  speed.  In  other  words,  a 
horse  that  trots  20  miles  a  day  must  have  more  food 
than  when  he  walks  the  20  miles.  In  the  same  w^ay 
draft  animals  require  food  somewhat  in  proportion  to 
the  pace  with  which  they  travel  over  a  given  distance. 
Grandeau  has  shown  that  a  horse  was  kept  in  condition 
with  19.4  lbs.  of  hay  when  he  walked  12%  miles,  but 
24  lbs.  was  insufficient  when  he  trotted  the  same  dis- 
tance. Zuntz  measured  the  oxygen  used  per  meter 
kilogram  when  a  loaded  horse  traveled  at  different 
velocities.  When  the  pace  was  three  miles  per  hour, 
with  a  load  of  275  lbs.,  the  energy  required  was  equal 
to  4,600  calories  for  each  kilogram  meter  of  horse, 
which  increased  to  7,753  calories  when  the  speed  reached 
6/3  to  1/i  miles  per  hour.  The  food  needed  per  unit 
of  w^ork  increased  nearly  70  per  cent  in  increasing  the 
speed  from  3  miles  to  7  miles.  Zuntz  shows  that  if  a 
horse  exerts  himself  to  the  utmost  the  use  of  oxygen 
rises  at  a  rapid  rate,  and  that  the  food  consumed  per 
unit  of  work  is  nearly  one -half  more  than  with  ordinary 


Food  Needs  of  a    Worl'ing  Horse  871 

draft.  It  appears  to  be  a  rule  that  as  the  intensity 
of  exertion  of  the  horse  inereases  the  food  cost  of  a 
given  amount  of  hibor  performed  increases.  Men  of 
experience  recognize  this  fact  in  a  general  way  when 
they  insist  on  favoring  their  animals  to  the  slow^est 
pace  that  is  consistent  with  the  conditions  involved. 

The  food  requirements  of  a  icorJcing  horse.  —  There 
are  two  general  ways  of  ascertaining  the  food  needs  of 
a  working  horse,  by  practical  experiments  in  which  the 
rations  are  varied  until  a  conclusion  is  reached  as  to 
what  will  support  an  animal  under  given  conditions, 
and  by  determining  through  scientific  investigations 
the  amount  of  work  performed  in  various  ways  and 
the  relation  of  a  unit  of  food  to  a  unit  of  work.  It 
would  not  be  far  from  the  truth  to  state,  however,  that 
the  feeding  standards  which  are  offered  to  us  through 
investigations  made  by  Boussingault,  Wolff,  LeClerc, 
Grandeau,  Hoffmeister,  Lavalard,  Zuntz,  Kellner,  and 
others,  are  the  outgrowth  of  both  practical  observations 
and  scientific  research,  a  most  desirable  combination. 
In  a  large  number  of  instances  the  kind  and  quantities 
of  digestible  food  consumed  daily  by  working  horses 
have  been  determined,  and  in  many  cases  the  accom- 
panying wastes  and  gain  and  loss  of  the  animal  body 
have  been  measured. 

The  standard  rations  now  found  in  German  tables 
are  the  result  of  such  observations.  According  to 
these  standards  a  1,000-pound  horse  requires  11.4  lbs. 
of  digestible  food  daily  Avhen  doing  moderate  work, 
13.6  lbs.  for  average  work,  and  16.6  lbs.  for  heavy 
work.    With  a  basal  ration  of  10  lbs.  of  hay  the  grain 


372  Tlie  Feeding  of  Animals 

needed  to  furnish  these  quantities  of  digestible  nu- 
trients, when  consisting  of  a  mixture  in  equal  parts 
of  corn  and  oats  would  be  approximately  11.5  lbs.,  15 
lbs.,  and  2)  lbs.  for  the  three  conditions  of  labor. 
Lavalard,  who  made  observations  covering  a  period  of 
a  number  of  years  for  32,000  omnibus,  army,  and  draft 
horses,  has  reached  the  conclusion  that  "a  horse  per- 
forming ordinary  work  requires  115  grams  of  diges- 
tible protein  and  1,100  grams  of  digestible  carbohy- 
drates per  100  kilograms  live  weight."  This  is  at  the 
rate  of  1.215  lbs.  of  digestible  nutrients  per  100  lbs.  of 
live  weight.  This  observer  bases  the  ration  upon  the 
weight  of  the  animal,  but  practically  concedes  that 
"somewhat  larger  amounts  of  protein  and  carbohy- 
drates are  considered  necessary  with  small  horses," 
a  conclusion  which  is  entirely  consistent  with  obser- 
vation and  related  facts.  Lavalard 's  formula  would 
furnisli  a  1,000-pound  horse,  doing  ordinary  work, 
with  12.1  lbs.  of  digestible  nutrients  daily,  a  quantity 
not  inconsistent  with  the  German  standard. 

It  seems  to  the  writer  that  the  results  of  the  mas- 
terly and  extensive  metabolism  investigations  which 
Zuntz  has  carried  on  with  a  horse  under  various  con- 
ditions may  properly  be  cited  in  this  connection.  This 
investigator  determined  the  oxygen  consumption,  which 
is  equivalent  to  ascertaining  the  food  use,  by  a  horse 
at  rest,  when  walking  on  a  smooth  level  without  load, 
and  when  performing  both  light  and  heavy  work. 
First  of  all,  it  appears  from  his  observations  that  31.6 
per  cent,  or  about  one-third,  of  the  total  food  energy 
can  be  converted  into  useful  work.     This  is  much  less 


Food  N'eeds  of  a    Worling  Horse  373 

than  the  coefficient  of  usefnl  work  fonnd  b}'  ^Yolff, 
whose  conclusions  Znntz  regards  as  erroneous.  But 
even  if  Zuntz's  figures  are  none  too  low,  it  is  evident 
that  the  animal  machine  uses  fuel  with  much  greater 
economy  than  a  steam  engine  where  the  coefficient  of 
usefulness  might  not  be  over  10  per  cent.  The  figures 
he  reached  show  further  that  the  total  expenditure  of 
energy  by  a  horse  weighing  1,000  pounds  in  walking 
one  mile  equaled  453  foot  tons,  which  would  be  fur- 
nished by  .164  lb.  of  digestible  food.  As  44.4  per 
cent  of  this,  or  201  foot  tons,  was  due  to  the  effort 
of  walking  over  and  above  the  needs  for  maintenance, 
the  extra  digestible  food  needed  per  mile  of  walking 
was  .07216  lb. 

Zuntz  also  found  that  when  a  horse  increases  the 
external  mechanical  labor  performed  such  increase  costs 
.001155  lb.  digestible  dry  matter  for  each  foot  ton  of 
work.  On  this  basis  the  264  foot  tons  of  energy 
which  is  needed  for  pulling  one  mile  a  load  with  a 
draft  of  100  lbs.  would  be  furnished  by  .3049  lb.  of 
food  matter.  The  total  food  expenditure,  therefore, 
for  walking  and  a  draft  of  100  lbs.  over  a  smooth, 
level  road  for  one  mile,  would  be  .377  lb.  digestible 
nutrients,  and  for  twenty  miles  7.54  lbs.  If  we  add 
to  this  the  6.4  lbs.  needed  for  mere  maintenance,  we 
have  13.94  lbs.  digestible  matter  as  the  proper  ration  for 
a  horse  doing  the  work  stated  for  a  distance  of  20  miles. 
These  figures  are  certainh'  not  inconsistent  with  the 
standard  reached  by  other  methods  for  a  horse  doing 
average  work.  Such  a  calculation  is  at  least  useful 
in  showing  the  direct  relation  of  food  expenditure  to 


374  The  Feeding  of  Animals 

work  performed,  and  the  necessity  of  feeding  a  labor- 
ing animal  somewhat  proportionately  to  what  he  does. 
It  should  be  borne  in  mind  constantly  that  when  the 
intensity  of  effort  of  the  horse  increases,  even  if  only 
the  same  work  is  performed  in  a  shorter  time,  the  food 
needs  per  unit  of  work  are  greater.  If  a  driver  in 
making  the  regular  number  of  trips  to  the  railroad 
station  needlessly  hurries  his  horse,  or  if  a  drayman 
whips  his  team  into  a  fast  walk  and  then  lets  it  stand 
idle,  more  food  must  be  consumed  than  if  the  slowest 
possible  gait  was  allowed. 

Source  of  the  ration  for  working  horses. — In  treating 
of  this  matter  we  must,  in  the  first  place,  consider  the 
digestive  apparatus  or  storage  capacity  of  the  horse. 
It  is  certainly  not  adapted  to  the  consumption  of  large 
quantities  of  coarse  food,  as  is  the  case  with  ruminants. 
If  a  horse  at  severe  labor  needed  17.7  lbs.  of  digesti- 
ble dry  matter  per  day,  he  could  get  it  from  hay  only 
by  eating  over  40  lbs. — a  most  absurd  requirement.  It 
is  especially  necessary,  therefore,  with  hard-working 
animals,  that  the  larger  part  of  their  nutriment  come 
from  the  concentrated  feeding  stuffs.  Ten  to  12  lbs. 
of  hay  is  all  a  draft  horse  should  consume  in  one  day. 
Working  horses  on  the  farm  generally  eat  Ibo  much 
coarse  fodder. 

The  net  values  of  feeding  stuffs  are  also  important 
in  this  connection.  It  has  been  shown  that  the  net 
energy  value  of  a  unit  of  digestible  matter  from  dry 
hay  is  less  than  with  tliat  from  the  gi-ains,  and  conse- 
quently when  it  is  necessary  to  supply  an  animal  with 
a  large  amount  of  energy  for  external  mechanical  uses, 


Proportion  Nutrienis  in    Worlt-Horse   Ration     375 

requiring-  high  feeding,  we  must  resort  to  the  grains 
in  order  to  construct  a  ration  of  maximum  efficiencj'. 

Concerning  the  nutritive  ratio  or  proportion  of  pro- 
tein, in  a  ration  designed  for  working  horses,  there  is 
a  variety  of  recommendations.  The  German  standards 
call  for  ratios  from  1:7  to  1:6,  according  to  the  severity- 
of  labor,  the  daily  weight  of  protein  for  a  1,000-pound 
horse  to  be  from  1.5  to  2.5  lbs.  This  is  greatly  more 
protein  than  is  recommended  by  Lavalard,  who,  on  the 
basis  of  extensive  experience,  declares  that  1.15  lbs. 
of  protein  daily  is  sufficient  for  ordinary  work,  this  to 
be  increased  to  1.35  lbs.  when  the  labor  becomes  more 
severe.  There  is  one  fundamental  fact  that  is  pertinent 
to  a  discussion  of  this  point,  which  is  that  the  non- 
nitrogenous  constituents  of  the  ration  are  largely  the 
source  of  muscular  power.  As  stated  before,  it  was 
formerl}-  thought  that  muscular  effort  was  sustained  at 
the  expense  of  muscular  tissue,  but  when  it  was  found 
that  no  more  urea  was  excreted  by  men  climbing  a 
mountain  than  when  they  were  much  less  active,  this 
view  was  abandoned.  Later  researches  have  clearly 
shown  that  when  work  increases  the  excretion  of  car- 
bon dioxid  increases  in  like  proportion,  without  any 
important  rise  in  the  protein  exchange.  In  other  words, 
the  carbohydrates  and  fats  are  largely  the  fuel  that 
supplies  energy  for  mechanical  purposes.  Common 
experience  ratifies  this  conclusion  of  science.  How 
many  horses  and  oxen  have  successfully  endured  severe 
labor  on  meadow  hay,  oats  and  corn,  sometimes  the 
grain   being  largely  the  latter! 

It  is  the  judgment  of  the  writer  that  a  ration  prop- 


376  The  Feeding  of  Animals 

erly  compounded  from  ordinary  farm  products,  such 
as  silage,  roots,  meadow  hay,  legume  hays  and  the 
cereal  grains,  will  generally  contain  protein  in  suffi- 
cient proportion,  and  will  seldom  need  reinforcing  with 
the  nitrogenous  feeding  stuffs.  It  is  probably  true,  how- 
ever, that  when  w^orking  animals  are  called  upon  to  en- 
dure a  severe  strain  material  advantage  is  gained  from 
introducing  into  the  ration  a  small  quantity  of  some 
nitrogenous  feeding  stuff,  such  as  beans  or  oil  meal. 

One  of  the  opinions  regarding  the  feeding  of  horses 
which  has  widely  prevailed  and  which  is  still  held  by 
many  is  that  oats  in  liberal  proportions  are  essential 
to  the  successful  maintenance  of  road  and  work  horses, 
especially  the  former.  It  has  been  believed,  as  has 
been  stated,  that  this  grain  imparts  to  the  horse  greater 
nervous  activity  or  life  than  any  other  feeding  stuff, 
and  when  it  was  announced  that  "avenine,"  an  alkaloid, 
had  been  extracted  from  oats,  this  was  quickly  accepted 
as  an  explanation  of  their  peculiar  effect.  We  have 
given  up  the  avenine  and  seem  likel}'  to  modifj^  our 
views  in  other  ways,  for  it  is  becoming  increasingly 
evident  that  other  grains  may  be  substituted  for  oats 
with  no  detriment  to  the  horse  and  with  a  material 
saving  to  his  owner.  Barley,  brewer's  grains,  maize, 
maize  cake,  wheat,  wheat  bran,  wheat  middlings,  have 
been  extensively  and  safely  fed  in  the  place  of  oats, 
wholly  or  in  part,  by  experiment  stations  and  in  prac- 
tice by  omnibus  and  horse -car  companies.  In  this  way 
the  cost  of  maintaining  horse  labor  is  materially  de- 
creased, for  usually  oats  are  comparatively  much  more 
expensive  than  other  grains  and  the  ])y- products  in  pro- 


Rations  for    Worlc- Horses 


377 


portion  to  their  feeding  value.  Unless  prices  change, 
a  farmer  can  generallj'  afford  to  sell  a  part  of  the  oats 
he  raises  and  buj'  other  grains,  and  he  can  do  this 
with  confidence  that  he  will  be  able  to  maintain  his 
road  and  working  horses  in  proper  flesh,  and  good 
health  and  spirit,  on  the  cheaper  materials. 

As  a  suggestion  to  feeders  concerning  the  ways  in 
which  several  feeding  stuffs  may  be  combined  so  as  to 
furnish  -practically  the  same  quantit}'  of  digestible  or- 
ganic matter,  the  following  rations  are  presented  as 
meeting  the  needs  of  a  horse  weighing  1,000  lbs.  and 
doing  moderate  work: 


10  lbs.  timothy  or  mixed  hay. 
IIX  lbs.  oats. 


r  10  lbs.  hay. 
10%  lbs.  oats  and  coi'n,  equal 


I 


parts  by  weight. 


r  10  lbs.  hay. 

\  lO/o    lbs.  oats   aud    barley, 


1 


10% 

equal  parts  by  weight. 

10  lbs.  hay. 
8  lbs.  oats. 
4  lbs.  brewer's  grains. 


('  10  lbs.  hay. 
<.  8  lbs.  oats. 
(    4  lbs.  wheat  bran. 


(  10  lbs.  hay. 

-s     5  lbs.  corn. 

(   4X  lbs.  barley. 

r  10  lbs.  hay. 

\     5  lbs.  corn. 

(^    6}{  lbs.  wheat  bran. 

r  10  lbs.  hay. 

^     5  lbs.  corn. 

(^    6  lbs.  brewer's  grains. 

f  10  lbs.  hay. 

1     4X  lbs.  barley. 

J     4  lbs.  wheat  bran. 

I     3  lbs.  brewer's  grains. 

f  10  lbs.  hay. 
J     3%  lbs.  corn. 
J     4  lbs.  wheat  bran. 
V    4  lbs.  brewer's  grains. 


Silage,  roots  and  other  green  materials  may  often 
be  substituted  for  a  minor  part  of  the  hay  with  advan- 
tage to  the  animal's  appetite  and  health. 


378  The  Feeding  of  Animals 

No  definite  rations  are  suggested  for  more  severe 
labor.  The  amount  of  food  must  simplj^  be  increased 
with  the  amount  of  work  performed.  Any  increase 
should  apply  to  the  grain  and  not  to  the  hay,  the  pro- 
portions of  the  several  feeding  stuffs  in  the  grain 
ration  to  remain  the  same  in  the  larger  quantity.  It 
is  well  understood,  of  course,  that  a  ration  should 
increase  proportionately  faster  than  the  amount  of 
work  done,  and  that  an  old  animal  generally  demands 
higher  feeding  than  does  a  young  one.  The  condition 
of  the  road,  the  intensity  of  the  effort  and  other  cir- 
cumstances also  modifj'  the  needs  of  the  working  horse, 
so  that  the  feeder  is  always  called  upon  to  exercise 
the  trained  judgment  which  comes  from  experience. 
No  working  animal  can  be  fed  successfully  by  meclian- 
ical  rules. 


CHAPTER    XXV 

THE   FEEDiyG    OF  POULTRY 
By  William   P.  Wheeler 

One  pronounced  characteristic  of  birds  is  an  in- 
tense vitality.  Their  life  is  never  sluggish.  The 
growth  of  the  young  and  the  transformation  of  food 
into  eggs  are  exceedingly  rapid.  The  temperature  is 
high,  running  with  different  species  from  a  little  above 
100°  F.  to  112°  or  more.  The  energy  expended  in  this 
direction  is  proportionately  great,  and  material  for  its 
supply  is  in  urgent  demand;  for  a  vigorous  animal  is 
the  seat  of  rapid  metabolic  change.  The  large  appe- 
tite is  an  indication  of  the  extensive  needs.  The  very 
active  digestive  apparatus  must  be  in  good  order  and 
supplied  with  efficient  food. 

The  domestic  fowls  may  be  classed  with  the  ma- 
jority of  birds  as  omnivorous.  While  seed-eaters  like 
the  common  fowl  are  able  to  subsist  for  long  periods 
on  grain  alone,  as  can  also  the  goose  by  grazing,  the 
natural  food  of  most  young  birds  is  largely  animal. 
Many  wild  birds  which  feed  almost  entirely  on  seeds 
supplj'  their  rapidly -growing  young  with  an  abundance 
of  animal  food. 

Kinds  of  foods. — It  is  a  common  experience  that 
better   success   follows  the  use  of   several   foods   com- 

(379) 


380  Tlie  Feeding  of  Animals 

bined  rather  than  a  few,  and  it  seems  to  be  a  fact 
that  some  variety  is  essential.  While  in  practice  a 
combination  must  be  employed  for  best  results  which 
are  partly  due  to  the  usually  greater  palatability  and 
other  indirect  effects  on  the  general  health,  it  is  not 
because  of  a  greater  nutritive  value  of  the  constitu- 
ents from  different  sources  that  the  different  foods  are 
needed.  The  important  consideration  seems  to  be  the 
proportion  of  constituents.  In  experiments  made  at 
the  New  York  Agricultural  Experiment  Station,  the 
better  results  from  rations  containing  animal  food 
were  found  to  be  largely  due  to  the  greater  amount  of 
mineral  matter,  chiefly  phosphate  of  lime,  in  the  ani- 
mal food  used.  When  rations  of  grains  naturally- 
lacking  in  ash  content  were  supplemented  by  bone  ash, 
their  efficiencj'  was  increased  without  addition  of  other 
food.  For  chicks  during  the  periods  of  most  rapid 
growth  the  rations  of  vegetable  origin  supplemented 
by  material  rich  in  phosphate  of  lime  w^ere  equal  or 
even  superior  to  rations  supplying  large  quantities  of 
animal  protein  and  fat.  For  laying  hens  the  time 
during  which  such  rations  were  equally  efficient  was 
limited  to  a  few  months.  Rations  containing  animal 
food  were  much  superior  for  ducklings,  although  the 
addition  of  bone  ash  to  rations  of  grain  and  other 
vegetable  food  notably  increased  their  efficiency. 

Although  it  is  possible,  for  some  purposes,  to  com- 
pound effective  rations  from  grain  alone  when  the 
deficiency  of  ash  is  made  good,  it  is  l^etter  in  practice 
to  use  some  animal  food.  A  variety  of  grain  food 
supplying  enough  nitrogenous  matter  is  not  always  to 


I 


Succulent  and  Bulimy  Foods  381 

be  found,  and  animal  foods,  when  rich  in  protein  as 
most  of  them  are,  prove  of  great  service;  for  with 
them  can  be  freely  fed  some  of  the  cheaper,  starchy 
foods,  typical  among  which  is  the  palatable  and  re- 
markably efficient  Indian  corn.  For  fattening  mature 
fowls  animal  food  is  not  so  important  except  when  its 
use  improves  the  palatability  of  the  ration.  This  last 
is  a  matter  always  to  be  considered. 

Suc(;ulent  vegetable  foods  are  eagerly  eaten  by  do- 
mestic fowls.  Aside  from  the  beneficial  effect  on  the 
health  of  the  birds,  it  is  important  to  use  such  foods 
so  far  as  possible,  for  the  nutriment  they  supply  is 
cheaply  obtained.  With  most  rations  the  more  nitrog- 
enous fodders,  such  as  clover,  alfalfa,  and  very  imma- 
ture grasses,  are  best.  These  foods  also  contain  more 
of  the  needed  lime  than  do  grains.  It  must  be  re- 
membered, however,  that  fowls  are  not  fitted  to  de- 
pend largel}^  on  such  bulky  materials  while  production 
is  rapid.  The  goose  is  better  adapted  than  most  birds 
to  live  \>y  grazing,  but  the  liberal  use  of  the  more 
concentrated  grain  and  animal  foods  has  been  found 
necessary  except  during  the  idle  season. 

At  the  time  of  greatest  qq^  production  the  choice 
of  bulkj^  foods  should  preferabh^  be  confined  to  those 
of  the  most  tender  and  succulent  nature.  Certain  ex- 
periments also  indicate  that  a  ration  which  contains 
any  considerable  proportion  of  dry  or  woody  coarse 
fodder,  although  finely  ground,  is  not  suited  to  young 
chicks,  and  that  only  the  more  succulent  kinds  of 
bulky  foods,  like  the  first  shoots  of  grasses  and  clovers, 
should  be  fed  in  the  fresh  condition.     After  the  birds 


382  The  Feeding  of  Animals 

approach  maturity  and  growth  is  slower,  so  that  a 
much  larger  proportion  of  the  food  is  used  for  main- 
tenance, and  during  colder  weather,  Avhen  the  heat 
from  the  extra  energy  required  for  digestion  is  useful, 
more  of  the  coarse  foods  can  be  fed  without  apparent 
disadvantage. 

Incidental  effects  of  the  food. — Another  reason,  some- 
times a  very  important  one,  for  using  such  foods  as 
young  clover,  fresh  or  dried,  is  the  effect  on  the  color 
of  the  egg -yolk.  Eggs  from  hens  which  are  fed  only 
certain  grain  and  animal  substances  generally  have 
yolks  of  a  pale  yellow  color.  This  is  often  objected 
to  by  those  who  have  a  preference  for  eggs  with  darker 
orange -colored  yolks.  The  liberal  feeding  of  fresh  or 
dried  j-oung  clover,  alfalfa  or  grass  will  generally  in- 
sure the  deeper  coloration.  The  cause  for  this  frequent 
lack  of  what  may  be  considered  the  normal  yellow 
color  of  the  egg -j-olk  is  not  well  known,  but  the 
occurrence  of  the  pale  color  can  be  generally  prevented 
by  attention  to  the  food. 

At  the  New  York  Experiment  Station  pens  of  hens 
which  were  fed  alike  except  that  no  hay  or  green 
food  was  given  to  one  while  three  others  had  different 
amounts,  apportioned  by  geometrical  ratio,  of  clover 
hay  alternated  with  green  alfalfa,  produced  eggs  show- 
ing marked  differences  in  color.  The  orange -yellow 
shade  of  the  yolk  corresponded  directly  in  intensity  with 
the  proportion  of  hay  or  green  fodder  in  the  ration. 
The  greenish  color  of  the  white  also  varied,  but  not  so 
regularly.  Eggs  from  each  lot  were  very  uniform  in 
appearance. 


The   Organs  of  Digestion  383 

The  diiferences  in  flavor  and  other  qualities  which 
are  probably  caused  by  the  food  cannot  be  satisfac- 
torily explained  at  present.  They  are,  however,  slight 
with  normal  rations.  In  general  the  color  of  the  shell 
is  determined  by  the  breeding  or  by  the  individual 
characteristics  of  the  fowl. 

Digestive  apparatus. — The  process  of  digestion  with 
birds  is  essentially  similar  to  that  with  mammals, 
although  there  are  important  differences  in  the  ap- 
paratus by  which  it  is  accomplished.  It  is  necessary 
to  know  something  of  the  general  arrangement  and 
working  of  the  digestive  canal  when  attempting  to 
establish  proper  methods  of  feeding,  and  for  a  better 
selection  and  combination  of  suitable  foods. 

Although  some  extinct  species  of  birds  were  well 
supplied  with  teeth,  existing  forms  have  the  mouth 
armed  onh-  with  a  horny  beak.  The  common  fowls 
must  swallow  grains  whole,  but  are  able  to  tear  some 
food  into  small  fragments,  which  they  particularly  do 
when  feeding  the  young.  Ducks,  and  geese  more  espe- 
cially, have  the  mouth  supplied  with  lamina,  which 
serve  to  cut  soft  herbage. 

In  birds  the  salivary  glands  are  small  and  the  lim- 
ited amount  of  saliva  probably  has  little  effect  on  the 
food. 

The  oesophagus  is  of  great  caliber  and  very  expan- 
sible. It  is  dilated  in  the  cervical  portion  in  ducks 
and  geese.  In  gallinaceous  birds,  instead  of  this  dila- 
tation there  is  attached  to,  and  forming  practically  a 
part  of,  the  oesophagus,  the  reservoir  called  the  crop. 
The  food  is   temporarily  retained  in  the   crop,   but  is 


384  The  Feeding  of  Animals 

changed  very  little  other  than  being  softened  by  the 
water  swallowed  with  it,  the  small  amount  of  mucus 
and  the  inconsequential  amount  of  saliva.  The  high 
temperature  doubtless  assists  this  softening  effect,  and 
fermentation  also  progresses  rapidly  when  food  is  re- 
tained long  in  the  crop  from  injury  or  by  overloading 
with  coarse  material. 

The  divided  crop  of  pigeons  secretes,  with  both 
sexes,  for  several  days  after  the  young  are  hatched, 
A  thick  milky  fluid  which  serves  to  feed  the  3'oung 
birds.  With  other  domestic  birds  the  crop  serves  for 
little  more  than  a  temporary  retaining  reservoir. 

The  stomach,  Avhich  is  a  single  organ  in  some  birds, 
is  represented  by  two  reservoirs  in  domestic  fowls. 
The  first,  through  which  the  food  passes  after  leaving 
the  crop,  is  the  glandular  stomach,  the  succentric  ven- 
tricle or  proventriculus,  and  the  second,  closely  con- 
nected, is  the  gizzard  or  muscular  stomach.  The  first, 
from  its  structure,  has  been  considered  the  true  stom- 
ach, but  it  is  now  believed  that  gastric  juice  is  secreted 
in  the  gizzard.  The  food  does  not  accumulate  in  the 
first  stomach,  but  in  passing  through  carries  along  such 
juices  as  are  there   secreted. 

The  gizzard  is  a  powerful  grinding  apparatus. 
There  is  a  strong  lining  which  is  capable  of  resisting 
great  pressure  and  the  action  of  the  sharp  sand  and 
pebbles.  In  this  organ  the  grains  and  seeds,  with 
other  materials,  are  more  finely  ground  than  by  the 
mastication  of  many  other  animals. 

The  intestines  are  long  in  domestic  fowls.  While 
serving  the  same   purpose   as   iu    mammals  and  having 


1    Tongue 

z    esofhaoos  jtirst  pobtioh 

3  Crop 

4  EsOPM^OUi      5fC0HD  PORTION 

5  5uccfNT«ic   Ventricle 

6  G  iZflRD 

7  O"?  C  N     OF     DUODENUM 
OECOND     6RDMCH     OF     BUODENAl.    FLEHORE 

9     Of  vH   OF  rtqATiNQ   ronTioN  of  small   intestih 

10.10  Small    iniestine 

11.11  C/ECA 

12  Insertion  of  c«tA 

1 3  TTectum 

14  ClOACA 

15-15     Pancreas 

16  LlVEl? 

17  Qall-BLAdder 

18  &F1.EEN 


Fig.  10.    Digestive  apparatus  of  odmmon  fowl. 


386  The  Feeding  of  Animals 

a  general  resemblance  to  the  mammalian  form,  they  do 
not  clearly  show  the  same  divisions.  The  diameter  is 
about  the  same  throughout.  The  ca3ca,  each  of  which 
is  closed  at  one  end  and  opens  into  the  intestines  at 
the  other,  seem  to  be  important  and  essential  modifi- 
cations of  that  canal.  Each  caecum  is  from  six  to 
seven  inches  long  in  mature  fowls.  Not  far  from  the 
openings  of  the  caeca  the  intestine  ends  in  a  dilatation, 
the  cloaca,  into  which  the  genito- urinary  passages  also 
open.  It  is  because  of  the  mixing  here  of  the  undi- 
gested residues  of  the  food  with  the  secretions  from 
the  kidneys  and  with  some  other  products  of  metabolism, 
that  an  accurate  estimation  of  the  digestibility  of  food 
by  birds  is  so  difficult.  No  satisfactorily  accurate 
methods  for  separating  some  of  the  nitrogenous  resi- 
dues from  different  organs  seem  yet  to  be  perfected. 

Into  the  intestine  shortly  after  it  leaves  the  gizzard 
two  ducts  from  the  liver  and  two  from  the  pancreas 
enter,  discharging  the  bile  and  pancreatic  juices.  The 
liver,  as  usual,  is  a  large  organ.  The  pancreas  also  is 
very  largely  developed,  and  extends  for  several  inches 
along  the  duodenal  loop  of  the  intestines,  reaching  in 
the  common  fowl  a  length  of  over  five  inches. 

Altogether  the  structure  of  the  digestive  apparatus 
of  birds  indicates  extreme  efficiency  and  the  capacity 
for  rapid  work.  A  study  of  it  suggests,  also,  as  does 
that  of  any  complicated  and  delicately  adjusted  appa- 
ratus, that  it  should  not  be  overloaded  nor  violently 
disturbed  when  running  at  high  pressure.  It  may  be 
said  to  run  at  high  pressure  while  the  extremely  rapid 
growth  of  young  birds  occurs,  and  during  the  extended 


Constructive  Material  Required  for  the  Bodtj    387 

laying  season,  for  the  resnlting  products  call  for  an 
uninterrupted  supply  of  food  and  the  transformation 
of  all  material  that  is  available.  Chickens  of  two 
pounds  weight  at  ten  weeks  of  age  show  a  gain  over 
the  weight  of  the  first  week  of  nearly  1,700  per  cent. 
Ducklings  five  pounds  in  weight  at  nine  weeks  show  a 
gain  during  about  eight  weeks  of  3,900  per  cent.  Such 
rates  of  growth  are  not  very  unusual  for  young  fowls 
under  favorable  conditions. 

CONSTITUENTS    OF    THE    BODY 

Whether  the  production  of  meat  or  of  eggs  is  the 
prime  object,  the  young  fowl  must  first  be  grown. 
It  is  desirable,  then,  to  consider  what  constituents  make 
up  the  body  of  the  animal,  for  all  must  be  derived 
from  the  food.  Many  slight  variations  in  composition 
exist,  of  course,  but  there  is  always  a  certain  approxi- 
mation to  the  normal  full-grown  animal. 

In  the  whole  body  of  the  common  fowl,  unless  espe- 
cially fattened,  not  far  from  one -half  of  the  dry  matter 
is  protein  and  about  8  per  cent  ash.  This  of  itself 
would  suggest  that  a  slow  growth  must  follow  the  use 
of  foods  containing  small  amounts  of  nitrogenous  and 
mineral   matter. 

Analyses  made,  mostly  by  Jenter,  at  the  New  York 
Experiment  Station,  give  as  the  average  composition 
of  the  body  of  a  Leghorn  hen,  typical  of  the  laying 
breeds,  55.8  per  cent  of  water,  21.6  per  cent  of  protein, 
3.8  per  cent  of  ash,  and  17  per  cent  of  fat.  This  is 
not  the  composition  of  the  edible  portion  alone  nor  of 


388  The  Feeding  of  Animals 

the  carcass  as  found  in  the  market,  but  that  of  the 
whole  body,  bones,  blood,  feathers,  and  all  the  viscera. 
The  different  parts  of  the  body  were  all  separately 
analyzed.  Separate  analyses  of  four  individual  hens 
each  gave  a  close  approximation  to  the  average.  The 
composition  of  the  body  of  a  Leghorn  pullet  in  full 
laying  was  little  different  from  the  average  for  the 
hens,  being  55.4  per  cent  of  water,  21.2  per  cent  of 
protein,  3.4  per  cent  of  ash,  and  18  per  cent  of  fat. 

The  body  of  a  mature  capon  (Plymouth  Rock)  con- 
tained 41.6  per  cent  of  water,  19.4  per  cent  of  protein, 
3.7  per  cent  of  ash,  and  33.9  per  cent  of  fat.  If  the 
extra  amount  of  fat  were  removed  the  composition  would 
be  very  similar  to  that  of  the  other  fowls.  In  younger 
and  immature  birds  the  percentage  of  fat  is  very  much 
less  than  in  older  birds. 

The  Q^^,  which,  aside  from  the  shell,  is  potentially 
a  chick,  shows  in  the  general  proportions  of  the  con- 
stituents a  striking  resemblance  to  the  body  of  the 
grown  bird.  Of  the  dry  matter  of  eggs  analyzed, 
aside  from  the  shell,  49.8  per  cent  on  the  average  was 
protein,  3.5  per  cent  ash,  and  38.6  per  cent  fat.  Of 
the  dry  matter  of  the  bodies  of  hens  48.9  per  cent  was 
protein,  8.6  per  cent  ash,  and  38.5  per  cent  fat. 

Of  the  total  dry  matter  in  the  entire  iigg  35.6  per 
cent  is  ash,  25.9  per  cent  fat,  and  about  33.3  per  cent 
protein,  or  38.5  per  cent  if  estimated  by  difference.- 
The  fresh  egg  with  a  good  firm  shell  consists  of  about 
11.4  per  cent  shell,  65.7  per  cent  of  water,  8.9  per 
cent  of  fat,  11.4  per  cent  of  protein  by  factor,  or  13.2 
per   cent   by  difference,   and  .8   per   cent  of   ash   con- 


The  Importance  of  Water  389 

stituents  aside  from  the  shell.  Of  this  ash  53.7  per 
cent  is  phosphoric  acid.  Over  .2  per  cent  of  the  edible 
portion  of  the  egg  is  phosphorus.  This  composition  is 
the  average  from  twentj'-four  analyses  by  Thompson, 
and  eighteen  by  Wheeler,  representing  over  400  eggs 
from  hens  of  several  breeds  under  different  rations. 
None  of  the  analyses  differed  much  from  the  average. 

Necessity  for  considering  the  water. — In  the  products 
which  have  been  mentioned,  as  in  most  animal  products 
sought  by  feeding,  there  is  always  a  large  amount  of 
water.  In  every  dozen  eggs  there  is  a  pint  of  water. 
Aside  from  that  necessary  for  constructive  use  there  is 
required  for  the  activities  of  the  living  animal  a  free 
supply.  Particular  mention  is  made  of  the  necessity 
for  water,  because  its  great  importance  is  sometimes 
overlooked,  for  an  especially  provided  supply  is  not 
necessary  under  some  circumstances.  Instances  occur 
when  the  lack  of  water  is  the  cause  of  ill  success. 

The  organic  and  mineral  nutrients  in  food. — Men- 
tion of  the  characteristics  and  composition  of  the 
different  nutrients  of  the  food  and  a  discussion  of 
their  functions  will  be  found  elsewhere  in  this  volume. 
The  facts  apply  to  the  feeding  of  poultry  as  well  as 
to  that  of  other  animals. 

It  appears  from  present  knowledge  that  protein 
derived  from  animal  sources  is  more  efficient  for  cer- 
tain uses,  particularly  the  feeding  of  ducklings,  than 
that  derived  from  vegetable  foods.  Previous  mention 
has  been  made  of  experiments  at  the  New  York  Ex- 
periment Station,  the  results  of  which  accord  with 
this  assumption.     The  rations  which  contained  animal 


390  The  Feeding  of  Animals 

food  proved  much  more  efficient  than  those  of  vege- 
table origin,  the  latter  having,  according  to  the  ordi- 
nary methods  of  estimation,  the  same  nutritive  value 
as  the  former. 

It  seems  probable  that  the  ash  constituents  have 
sometimes  not  been  sufficiently  considered  in  feeding. 
While  the  importance  of  the  mineral  nutrients  can  be 
largely  overlooked  without  serious  practical  disadvan- 
tage when  feeding  some  animals  for  certain  purposes, 
it  must  be  given  consideration  when  feeding  domestic 
fowls.  While  in  milk,  for  instance,  about  5  per  cent 
of  the  dry  matter  is  ash,  in  eggs  over  35  per  cent 
of  the  dry  matter  is  represented  by  the  mineral  con- 
stituents. 

The  shell  of  the  Qgg,  which  represents  about  11 
per  cent  of  the  fresh  egg,  consists  almost  entirely  of 
carbonate  of  lime.  Most  grain  foods  which  naturally 
constitute  the  bulk  of  ordinary  rations  contain  little 
mineral  matter  and  the  amount  of  lime  is  notably 
low.  For  simply  supplying  the  deficiency  of  material 
for  the  ^gg  shell,  carbonate  of  lime  in  the  form  of 
oyster  shell  can  be  used.  This  w^as  shown  in  experi- 
ments at  the  New  York  Experiment  Station  mnde 
with  laying  hens  after  they  were  closely  confined  on 
a  clean  floor  for  over  three  weeks.  It  was  then  found 
that  about  nine -tenths  of  the  lime  in  the  Qgg  shell 
was  unaccounted  for  in  the  food  aside  from  the  oyster 
shells  which  were  fed. 

While  less  than  10  per  cent  of  the  body  of  a 
fowl  is  mineral  matter,  it  consists  largely  of  phosphate 
of  lime  and  exceeds  in  proportion  that  of  many  foods. 


Salt  and   Grinding  Material  391 

The  bony  framework  is  also  rapidly  formed  in  the 
growing  bird,  so  that  mineral  matter  is  in  imperative 
demand.  The  results  of  many  trials  made  at  the  New 
York  Experiment  Station  are  clearly  in  accord  with 
this  assumed  need.  As  has  been  previously  men- 
tioned, the  addition  of  phosphate  of  lime  from  several 
sources  to  rations  for  young  fowls  has  noticeabl}^ 
increased  their  efficiency. 

Common  salt  in  considerable  quantity  is  a  neces- 
sity to  the  living  animal.  Some  foods  contain  a 
probably  sufficient  amount,  but  in  others  the  propor- 
tion is  very  small.  In  order  to  make  sure  of  an 
excess  and  to  avoid  any  possible  deficiency  it  is  well 
to  add  salt  regularly  to  the  food,  especially  when  it 
also  increases  the  palatabilitj'  of  the  ration.  About 
five  ounces  in  every  100  lbs.  of  food  has  been  found 
a  safe  proportion.  Fowls  regularly  accustomed  to  salt 
are  not  likely  to  eat  an  injurious  quantity  of  very 
salty  material  when  it  is  accidentally  within  their 
reach.  Pigeons  are  very  fond  of  salt  and  a  liberal 
allowance  is  generally  considered  necessary  to  insure 
health  in  the  loft. 

Fowls  at  liberty  are  generally  able  to  find  grit 
enough  in  the  form  of  sharp  pebbles  and  sand  to  facili- 
tate the  grinding  which  occurs  in  the  gizzard.  When 
they  are  confined  or  do  not  have  extended  range, 
sharp  and  hard  grit  of  some  kind  should  always  be 
freely  supplied.  Clean,  sharp  sand  is  useful  for  the 
very  young  birds,  and  is  quite  generally  considered  an 
essential  part  of  all  mixtures  fed  to  ducklings.  Good 
results  accompany  its  free  use. 


392  The  Feeding  of  Animals 

THE   STUDY   OF    RATIONS   AND   DEDUCTION   OP   STANDARDS 

In  studying  and  comparing"  different  rations,  it  is  not 
possible  to  consider  all  the  combinations  that  can  be 
made  of  the  many  foods.  It  is  only  practicable  to  con- 
sider foods  with  reference  to  their  varying  proportions 
of  constituents.  The  only  portion  of  these  constitu- 
ents of  nutritive  value  is  that  which  can  be  digested. 
Therefore,  in  compounding  rations,  we  are  guided  pri- 
marily by  the  amount  of  the  digestible  nutrients  supplied 
by  the  food;  and  feeding  standards  are  for  convenience 
limited  to  a  statement  of  the  assumed  requirements  in 
terms  of  digestible  protein,  ash,  carbohydrates  and  fat. 
The  bulk  of  the  ration  supplying  these  nutrients  must 
also,  of  course,  fall  within  certain  limits.  In  the  ab- 
sence of  enongh  specific  data  calculations  must  be  based 
on  the  coefficients  of  digestil)ility  observed  for  other 
animals.  These  afford  safe  enough  approximations  for 
present  use,  for  the  feeding  standards  must  be  largely 
provisional. 

Growth  and  Qgg  production  can  only  be  sustained 
by  the  food  in  excess  of  that  required  to  support  life, 
although  e^g  production  can  temporarily  occur  at  the 
partial  expense  of  the  body.  The  amount  of  food, 
then,  required  for  simple  maintenance  puts  a  limit  on 
one  side  to  an  efficient  and  profitable  ration.  In  the 
other  direction,  it  is  only  limited  by  the  capabilities  of 
the  individual  animal.  So  the  highest  possibilities 
depend  altogether  on  the  intelligent  judgment,  and 
careful,  daily  attention  of  the  experienced  feeder.  In 
a  general  way  only  averages  can  be  considered. 


Food  Required  for  Maintenance  393 

Maintenance  rations. — A  number  of  feeding  trials 
made  at  the  New  York  Experiment  Station  supply  in- 
formation relative  to  the  amount  of  food  required  for 
simple  maintenance.  The  amount  varies,  as  might  be 
expected,  with  the  size  of  the  animal.  The  larger  fowls 
required  more  food,  but  much  less  for  each  pound  of 
live  weight.  These  feeding  trials  did  not  cover  any 
molting  period  and  Qgg  production  was,  for  the  time, 
suspended.  From  the  data  secured  maintenance  ra- 
tions have  been  deduced  which  correspond  very  closely 
to  those  actuallj^  fed  for  quite  extended  periods  during 
which  practically  no  change  in  live  weight  occurred. 
The  data  were  from  an  aggregate  of  fifty-two  capons, 
averaging  by  different  lots  from  9  to  12  lbs.  in  weight, 
for  158  daj'S'  feeding,  and  from  sixty  hens  ranging 
from  3  to  7  lbs.  in  weight  for  150  days'  feeding. 

The  rations  are  stated  in  the  following  tabulated 
form  : 

Maintenance  Rations 

Digestible  nutrients  per  day  for  each  100  pounds  live  tceight 

Total  dry  C.irbohy-               Fuel  Nutritive 

matter  Ash  Protein  drates  Fat  value       ratio 

lbs.  lbs.  lbs.  lbs.  lbs.      Cal. 

Capons  of9  to  12  lbs.  wt... 2. 30  .00  .30  1.74  .20  4,G00        1:7.5 

Hens  of  5  to  7  lbs.  weight.. 2. 70  .10  .40  2.00  .20  5,300        1:0.2 

Hens  of  3  to  5  lbs.  weight.. 3.90  .15  .50     .  2.95  .30  7.080        1:7.4 

nations  for  laying  hens. — Hens  in  full  laying  seem 
to  require  rations  which  have  a  larger  relative  content 
of  protein  and  ash,  and  which  show  an  increase  in 
fuel  value  of  from  15  to  40  per  cent,  according  to  size, 
over  those  required  for  maintenance.  The  following 
standards  approximate  the  requirements  : 


394  The  Feeding  of  Animals 

Rations  for  Hens  in  Full  Laying 
Digestible  nutrients  per  day  for  each  100  pounds  live  iveight 

Total  dry  Carbohy-               Fuel  Nutritive 

matter      Ash  Protein  clrates  Fat  value  ratio 

lbs.         lbs.  lbs.  lbs.  lbs.     Cal. 

Hens  of  5  to  8  lbs.  weight.. 3.30          .20  .65  2.25  .20  6,240  1:4.2 

Hens  of  3  to  5  lbs.  weight.. 5.50          .30  1.00  3.75  .35  10,300  1:4.6 

These  standards  are  not  absolute  and  inflexible 
rules,  for  such  would  not  be  justified  by  a  thousand 
times  the  number  of  available  data.  They  supply  a 
definite  starting-  point,  and  are  not  supposed  to  obviate 
the  use  of  judgment.  Because  it  is  found  convenient, 
on  account  of  different  requirements  and  capabilities, 
to  divide  hens  into  two  groups,  it  should  not  be  pre- 
sumed that  a  hen  just  under  five  pounds  in  weig-ht 
must  always  have  one  ration  or  a  hen  just  over  five 
pounds  must  always  have  the  other. 

A  ration  which  corresponds  to  the  standard  given 
for  maintenance  for  hens  of  the  larger  size  could  be 
composed  of  one  pound  of  cracked  corn,  one  pound  of 
corn  meal,  one -half  pound  each  of  ground  oats,  wheat 
middlings,  and  clover  hay,  one -fourth  pound  of  fresh 
bone  and  two  ounces  of  meat  scraps. 

The  following  stated  ration  is  given  as  an  illustra- 
tion of  one  which  would  supply  the  nutrients  called  for 
in  the  standard  for  laying  hens  of  the  larger  size:  One 
pound  of  cracked  corn,  three -fourths  pound  of  wheat, 
three-fourths  pound  of  corn  meal,  one -half  pound  each 
of  wheat  middlings,  buckwheat  middlings,  and  animal 
meal,  two-thirds  of  a  pound  of  fresh  bone,  and  three- 
fourths  of  a  pound  of  young  green  alfalfa. 

Rations  for  young  birds. -^  The  requirements  of  the 


standard  Rations  for    Young  Fowls  395 

rapidly- growing'  youug  fowl  are  so  constantly  chang- 
ing that  a  satisfactory  average  ration  for  anj-  extended 
period  cannot  be  easilj'  formulated.  In  the  following 
statement  of  rations  for  chicks  they  are  averaged  for 
periods  of  two  weeks  at  different  ages  during  the  time 
of  most  rapid  growth.  The  ration  for  the  last  period 
will  suffice  for  several  weeks  louger,  although  the 
amount  required  per  100  pounds  live  weight  will  grad- 
ually diminish  up  to  maturity.  For  fattening  nearly 
mature  fowls  a  ration  with  a  wider  nutritive  ratio  of 
about  1:8  can  be  liberally  fed  for  limited  periods. 

The  duck  grows  faster  than  the  common  fowl,  and 
more  food  is  required  during  an  equal  time.  Rations  for 
ducklings  differing  somewhat  from  those  for  chicks  are 
given  separately. 

Rations  for  Chicks 

Digestihle  nutrients  per  day  for  each  100  pounds  live  weight 


Total  diy 

Pro- 

Carbohy 

Fuel 

Xutritiv 

matter 

Ash 

tein 

drates 

Fat 

value 

ratio 

• 

lbs. 

lbs. 

lbs. 

lbs. 

lbs. 

Cal. 

For  the  first  2  weeks 

.      10.1 

.5 

2.0 

7  2 

.4 

18,800 

1:4.1 

From  2  to  4  weeks  of  age. . 

9.G 

.7 

2.2 

G.2 

.5 

17.730 

1:3.4 

From  4  to  G  weeks  of  age . . 

8.G 

.G 

2.0 

5.G 

.4 

1.=;.640 

1:3.3 

From  6  to  8  weeks  of  age. . 

7.4 

.5 

l.G 

4.9 

.4 

13,780 

1:3.7 

From  8  to  10  weeks  of  age. 

G.4 

.5 

1.2 

4.4 

.3 

n.GSO 

1:4.3 

From  10  to  12  weeks  of  age 

5.4 

.4 

1.0 

3.7 

.3 

10,000 

1:4.4 

Rations  for  Ducklings 
Digestihle  nutrients  per  day  for  each  100  pounds  live  iveight 


Total  drj 
matter 

Ash 

Pro- 
tein 

Carlwhy 
drates 

Fat 

Fuel 
value 

Nutritive 
ratio 

lbs. 

lbs. 

lbs. 

lbs. 

lbs. 

Cal. 

For  the  first  2  weeks 

.      17  2 

l.G 

4.0 

11.2 

1.4 

34,180 

1:3.7 

From  2  to  4  weeks  of  age. . 

.      17.0 

1.5 

4.1 

10.1 

1.3 

31,900 

1:3.2 

From  4  to  6  weeks  of  age . . 

.      11.2 

.8 

2.7 

7.0 

.7 

21,000 

i:3.3 

From  6  to  8  weeks  of  age. . 

.        8.0 

.G 

1.7 

5.2 

.5 

14,940 

1:3.8 

From  8  to  10  weeks  of  age. 
From  10  to  15  weeks  of  age 

7.0 
.       4.6 

.5 
.3 

1.4 
.9 

4.7 
3.2 

.4 

.2 

13,030 
8,470 

1:4.1 
1:4.1 

396  The  Feeding  of  Animals 

As  an  example  of  a  day's  ration  which  would  cor- 
respond to  the  requirements  of  the  standard  given  for 
young  chicks  during  the  second  week  the  following  is 
stated:  Four  pounds  of  cracked  wheat,  two  pounds  of 
granulated  oat  meal,  three  pounds  of  corn  meal,  one- 
half  pound  each  of  wheat  middlings,  buckwheat  mid- 
dlings, ground  oats  and  old  process  linseed  meal,  two 
and  one -fourth  pounds  of  animal  meal  and  two  and 
three -fourths  pounds  of  young  green  alfalfa.  This 
would  feed  from  eight  hundred  to  a  thousand  chicks 
of  this  age. 

Another  ration  in  accord  with  the  standard  given 
for  ducklings  about  three  weeks  old  might  be  constituted 
as  follows:  Eight  pounds  corn  meal,  three  pounds  wheat 
middlings,  two  pounds  ground  barley,  two  pounds  of 
old  process  linseed  meal,  six  pounds  of  animal  meal, 
two  pounds  of  fresh  bone  and  three  pounds  of  young 
green  alfalfa.  This  and  other  specimen  rations  are 
given  under  the  assumption  that  free  supplies  of  sharp 
.grit,  as  well  as  water,  are  also  provided. 

A  consideration  of  the  adaptability  of  the  different 
foods,  aside  from  their  composition,  and  of  the  appar- 
ent requirements  of  the  j'oung  at  different  periods  sug- 
gests a  ration  somewhat  wider  in  nutritive  ratio  for 
the  first  few  days  than  for  some  weeks  afterward. 

In  providing  a  ration,  it  may  be  possible  to  devise 
one  in  accord  with  the  formal  standard  which  will  be 
decidedly  inefficient  at  times  if  the  chemical  composition 
and  coefficients  of  dig(^stibility  are  alone  considered. 
The  adaptability  of  foods  that  are  palatable  must  be 
considered.     The  difference   in   the  energy  required   to 


The  AdaptahiUUj  of  Certain  Foods  397 

digest  various  foods  which  can  supply  equal  proportions 
of  digestible  matter  may  be  also  at  certain  times  an 
important  factor. 

A  large  number  of  the  ordinary  grains  seem  prac- 
tically interchangeable  and  many  grain  by-products  can 
be  freely  substituted  for  different  whole  grains  or  for 
each  other  and  all  combined  as  desired.  But  some 
foods,  such  as  cottonseed  meal,  do  not  seem  suited  to 
common  fowls,  even  in  very  small  quantities.  Linseed 
meal  can  be  fed  more  freely,  but  the  unground  flax- 
seed is  less  satisfactory.  It  is  probable  that  oats, 
whole  or  ground,  which  appear  so  valuable  sometimes, 
should  not  be  freely  used  at  other  times.  About  thirty 
per  cent  of  the  entire  grain  is  hull.  To  obtain  the 
available  material  from  this  requires  an  expenditure 
of  energy  that  can  be  better  applied  during  periods  of 
rapid  transformation,  especially  during  the  first  few 
weeks  of  the  young  bird's  growth.  The  products  of 
the  oat  kernel,  however,  from  which  the  hull  has  been 
separated  are  in  the  unquestioned  class  of  foods.  The 
same  observation  applies  to  buckwheat,  some  kinds  of 
pea  meal  and  to  certain  other  foods  less  commonly 
used,  containing  a  large  proportion  of  crude  fiber. 
Reference  to  this  point  has  been  made  before  under 
the  topic  of  coarse  and  bulky  foods. 

Primary  consideration  has  naturally  been  given  to 
those  domestic  fowls  upon  which  we  depend  for  the 
great  bulk  of  eggs  and  meat.  Other  kinds  are  of 
considerable  importance  in  certain  localities,  or  often 
to  the  fancier,  but  concerning  them  not  enough  is 
recorded   to    establish   separate   feeding   standards.     It 


398  The  Feeding  of  Animals 

is  probable  that  their  requirements  will  be  found  to 
correspond  fairly  well  with  those  of  either  the  duck 
or  of  the  common  fowl.  The  general  food  of  the  tur- 
key is  similar  to  that  of  the  connnon  fowl,  but  it  should 
be  less  artificial,  and  conditions  of  general  feeding- 
more  nearly  resembling  those  which  exist  in  a  wild 
state  are  required. 

Unsatisfactory  as  is  our  present  knowledge  of  the 
fundamental  laws  which  underlie  the  science  of  nutri- 
tion applied  to  man  and  other  animals,  there  are 
nevertheless  volumes  of  carefully  collected  data  that 
make  it  possible  to  ascribe  fairly  narrow  limits  to 
their  operations.  Compared  with  mammals,  however, 
the  class  of  birds  has  received  very  little  considera- 
tion. There  have  been  a  few  careful  studies  made, 
but  for  lack  of  enough  information  our  feeding  nnist 
be  guided  by  the  rules  applying  in  common  to  all 
animals.  Undoubtedly  the  accepted  laws  of  nutrition 
observed  for  other  animals  are  applicable  in  a  general 
way  to  domestic  fowls,  and  it  is  safe  to  apply  in  the 
light  of  the  specific  data  we  have  any  general  prin- 
ciples of  feeding  that  have  already  been  established. 
This  has  been  done  in  formulating  the  feeding  stand- 
ards which  are  here  presented,  and  all  available  data 
of  a  reliable  character  have  been  considered.  There 
have  not  been  enough,  however,  to  justify  narrow 
limitations,  and  the  suggested  standards  should  not 
be  considered  final  and  unchangeable.  They  simply 
represent  the  averages  of  rations  which  under  careful 
management  and  like  conditions  have  given  better 
results    than    various   other    rations    with    which    they 


Modifications  of  the   Standard  Important        399 

have  been  contrasted.  Slight  modifications  were  made 
in  accord  somewhat  with  the  habits  of  the  different 
fowls  and  with  a  consideration  of  the  character  of 
the  products  desired.  It  is  important  that  the  feeder, 
while  following  such  standards  in  a  general  way, 
should  give  enough  consideration  to  the  subject  to 
make  modifications  suited  to  the  species  and  breed 
and  to  his  particular  conditions  of  market  and  farm. 


CHAPTER   XXVI 

THE  RELATION  OF  FOOD    TO   PRODUCTION 

One  of  the  questions  much  discussed  by  farmers, 
and  which  has  an  important  bearing  upon  the  eco- 
nomics of  animal  husbandry,  is  the  food  cost .  of  the 
various  animal  products.  To  illustrate,  a  herd  of  cows 
consumes  a  certain  quantity  of  food  and  produces  a 
certain  weight  of  milk,  milk  solids,  cheese  or  butter, 
according  to  the  terms  in  which  we  state  the  produc- 
tion. If  the  same  food  is  fed  to  a  lot  of  steers  a  cer- 
tain increase  in  their  live  weight  is  secured.  There  is 
in  each  case  a  relation  of  quantity  between  the  food 
and  the  product.  The  food  cost,  that  is,  the  food  con- 
sumption, involved  in  growing  a  pound  of  beef,  is  quite 
unlike  the  food  requirements  for  producing  a  pound 
of  pork,  a  pound  of  veal  or  a  pound  of  eggs.  If  we 
consider  merely  food  expenditure,  that  branch  of  ani- 
mal husbandry  is  most  economical  of  raw  materials  in 
which  the  largest  proportion  of  the  food  dry  substance 
is  converted  into  some  new,  useful  product,  or,  differ- 
ently stated,  where  the  food  units  bear  the  lowest  ratio 
to  a  unit  of  product. 

In  presenting  the  matter  it  is  necessary  to  first  de- 
fine our  units.  What  shall  we  accept  as  a  food  unit! 
Certainly  it  cannot  be  a  pound  of  food  as  eaten.     One 


Food    Cost  of  Production  401 

farmer  feeds  his  cows  silage  or  roots,  and  grain,  with 
but  little  hay,  w^hile  another  fattens  steers  on  dry  food 
alone.  A  comparison  of  production  in  the  two  in- 
stances on  the  basis  of  the  gross  weight  of  food  con- 
sumed w^ould  be  absurd,  because  wdth  the  cows  the  dry 
matter  is  largely  diluted  with  Avater.  It  would  be 
equally  absurd  to  accept  the  dry  matter  in  the  ration 
as  a  standard.  In  instituting  a  comparison  between 
bovines  and  swine  we  must  remember  that  the  former 
consume  materials  much  less  digestible  than  do  the 
latter,  and  so  a  unit  weight  of  food  does  not  represent 
the  same  w^eight  of  available  nutrients  with  the  two 
classes  of  animals. 

We  should,  so  far  as  possible,  reduce  rations  to 
their  units  of  nutritive  value,  and  so  the  digestible 
dry  matter  is  now  the  nearest  approach  we  can  make 
to  a  basis  for  comparing  rations  with  each  other  or 
with  the  production  wiiich  they  sustain.  It  follow^s, 
then,  that  if  we  wish  to  show  the  comparative  economy 
of  production  in  dairy  farming  and  in  beef  farming, 
food  alone  considered,  we  should  express  this  relation 
on  one  side  in  terms  of  digestible  dry  food  substance. 

What  shall  we  consider  as  a  unit  of  production  ? 
We  may  answer  this  question  from  two  standpoints. 
We  may  measure  production  by  the  quantity  of  the 
commercial  article  which  the  farmer  places  on  the 
market,  or  by  the  actual  contribution  which  any 
given  production  makes  to  the  food  resources  of  the 
human  family.  More  specifically  stated,  we  may  deter- 
mine the  relation  of  a  unit  of  digestible  food  sub- 
stance   to    the    live    animal,    beef,   pork,   milk,   cheese. 


402  The  Feeding  of  Animals 

butter  or  eggs  resulting  from  its  use,  and  calculate 
the  ratio  of  any  one  of  these  to  the  actual  nutrients 
consumed,  or  we  may  ascertain  the  ratio  of  food  con- 
sumption to  the  edible  dry  substance  in  the  various 
animal  products.  The  latter  is  the  important  ratio  to 
consider  if  we  are  seeking  to  learn  how  we  can  most 
efficiently  apply  farm  crops  to  the  sustenance  of  the 
human  family. 

This  study  of  food  economics  requires  a  knowledge 
of  several  factors.  In  the  first  place,  we  must  have 
the  information  coming  from  feeding  experiments, 
where  a  careful  record  has  been  kept  of  the  kind  and 
amount  of  food  consumed  and  of  the  weight  of  the 
resulting  growth,  milk,  eggs,  or  what  not.  This  in- 
formation must  be  supplemented  by  a  knowledge  of 
the  digestibilit}^  of  feeding  stuffs,  of  the  ratio  between 
the  live  animal  or  other  gross  product  and  the  com- 
mercial products  and  of  the  composition  and  propor- 
tion of  edible  material  supplied  by  the  commercial 
article.  For  instance,  we  find  it  takes,  on  the  average, 
7.40  lbs.  of  digestible  organic  substance  in  the  ration 
to  produce  one  pound  of  growth  in  a  steer,  and  we 
have  learned  by  slaughter  tests  that  the  average  per 
cent  of  carcass  for  97  animals  was  61.4,  and  by  the 
butchers'  and  chemists'  analyses,  that  the  carcass 
contains  an  average  of  33.2  per  cent  of  edible  dry 
matter.  From  these  data  it  is  easy  to  calculate  that 
12  lbs.  of  digestible  food  are  needed  for  the  growth 
of  one  pound  of  carcass  or  36.3  lbs.  for  the  growth 
of  one  pound  of  edible  beef  solids. 

The  following  tables  give  the  data  upon  which  is 


Productivity  of  Farm  Animals  403 

based  the  productive  power  of  food  Avheu  utilized  by 
the  various  chisses  of  auimals.  Data  of  this  kind  are 
practically  our  only  means  of  studying  the  economics 
of  producing  those  human  foods  which  are  most  costly 
in  proportion  to  their  nutritive  value,  a  studj'  which  is 
very  important  wherever  it  becomes  necessary  to  econo- 
mize energy.  It  shows  the  coefficients  of  efficiency  of 
various  species  of  animals  in  maintaining  the  human 
species.  The  sources  of  all  these  figures  are  not  given, 
for  they  are  so  numerous  as  to  make  this  difficult : 

Production  by  Farm   Animals 

Proportions  of  carcass  and  edible  substance 

Carcass        Per  cent*  Per  cent  of 
Number      in  per  cent    of  edible        edible  dry 

of  of  live       dry  matter  matter  in  live 

animals         weight        in  carcass         animal 

Steers,  general  average  97  61.4  33.2  20. -4 

Steers,  Iowa 5  6-1.  33.2  21.2 

Steers,  Kansas 5  61.4  33.2  20.4 

Steers,  Mainet  8  57.7  32.3  18.6 

Sheep 4  50.7  37.4  19. 

Lambs 44  50.7  33.7  17.1 

Lambs,  Iowa 133  54.  33.7  18.2 

Swine,  general  average  97  81.2  62.7  50  9 

Pigs,  Iowa 56  77.9  62.7  48.8 

Calves 23  57.2  22.2  12.7 

Fowl,  large 12  80.8  27.  21.8 

Fowl,  small 7  78.  27w    .          21.1 

Chickens,  broilers 107  82. Ij  14.7  12.1 

Eggs 34§  88.811  26.3  23.3"* 

*  From  Bull.  28,  Office  of  Experiment  Stations.     Revised  edition. 
t  Grown  from  calfhood,  entire  bodies  analyzed. 
tNot  drawn. 
§  Number  of  samples. 
II  Per  cent  after  removing  shells. 
**  In  eggs  with  shells. 


404 


The  Feeding  of  Animals 


Eelatlon  of  food  to  product 

Diges-         Diges-  Diges- 
tible oi-g.  til)le  org.  tible  org. 
substance  substance  substance 
Number                     produc-  produc-  producing 
of       Number    ingllb.  ing  1  lb.  lib.  in- 
expei-i-        of          increase  increase  crease 
ments    animals     live  wt.       carcass  edible  sol. 
lbs.              lbs.  lbs. 

Milk,  average 61  391           .72  5.55 

Milk,  New  York* 113t  30           .63  4.85 

Steers,  average :"2  242  7.40  12.  36.3 

Steers,  la.,  growth 9  to 24  m.  i  5  5.97  9.33  28.1 

Steers,  Kansas,  3  years  old.  1  8  8.08  13.16  39.6 

Steers,  Maine 1  4  6.65  11.5  35.7 

Sheep  and  lambs,  average..  11  122  7.20  14.2  37.9 
Lambs,  Iowa,  growth  while 

fattening 2  133  5.63  10.43  30.9 

Swine, t  average 277  1,385  3.29  4.  6.4 

Pigs,  Iowa 1  56  3.03  3.89  6.2 

Calves,  average 3  30  1.57§  2.70  12.3 

Fowl,  large,  to  5  or  6  mos.  II  6  5.10  6.30  23.4 

Fowl,  small,  to  5  or  6  mos.  II  6  5.10  6.50  24.2 

Chickens,  broilers,  12  wks.  II  15  3.48**  4.20  28.8 

Eggsll 14  139tt  4.56tt  5.10  19.6 

The  figures  of  the  foregoing  tables  can  be  regarded 
as  being  trustworthy  for  average  conditions.  They  are 
obtained  from  the  recorded  data  of  experiment  stations, 
and  involve  a  large  number  of  observations  with  dairj^ 
cows  and  with  growing  and  fattening  animals. 

In  most  cases  the   amount  of  digestible   matter  in 

*  Extending  over  seven  years. 
t  Short  periods. 

I  Deduced  from  compilation  by  Dr.  Armsby  for  U.S.  Dept.  of  Agriculture. 
§  Dry  matter,  mostly  from  milk,  practically  all  digestible. 

II  Unpublished  data  from  experiments  at  the  New  York  Agri.  Expt.  Station. 
*"'=4.3.3  lbs.  dry  matter,  assumed  to  be  80  per  cent  digestible. 

tt  Egg  product,  100  eggs  per  year. 

XX8  5.70  lbs  dry  matter,  assumed  to  be  80  per  cent  digestible. 


Relative  Food   Cost  of  Animal  Products        405 

the  ration    is  calculated   from   the  average  coefficients 
of  digestibility. 

The  facts  brought  out  h\  this  study  of  the  relation 
of  food  to  product  are  emphatic  and  suggestive.  In 
order  to  display  them  as  clearly  as  possible  there  are 
shown  in  the  next  table  the  quantities  of  the  various 
commercial  animal  products,  and  of  human  food  in 
animal  forms,  which  can  be  produced  hy  the  use  of  a 
quantity  of  cattle  food  containing  100  lbs.  of  digesti- 
ble organic  matter: 

Eelation  of  food  to  product 

Produced  by  100  lbs.  digestible  or- 
ganic matter  in  ration. 
Marketable  Edible 

product  solids 

lbs.  lbs. 

Milk,  general  average 139.  18. 

Milk,  New  York  experiments 158.7  20.6 

Cheese,  green 14.8  9.4 

Butter 6.4  5.44 

Steers,  general  average,  live  weight..  .     13.5 

Steers,  Iowa,  live  weight 16.8 

Steers,  Kansas,  live  weight 12.4 

Steers,  Maine,  live  weight 15. 

Steers,  general  average,  carcass 8.3  2.75 

Steers,  Iowa,  carcass 10.7  3.56 

Steers,  Kansas,  carcass 7.6  2.52 

Steers,  Maine,  carcass 8.7  2.84 

Sheep    and    lambs,    general    average, 

live  weight 13.9 

Lambs,  Iowa,  live  weight 17.8 

Sheep    and    lambs,    general    average, 

carcass 7.  2.60 

Lambs,  Iowa,  carcass     9.6  3.23 

Swine,  general  average,  live  weight. .  .     30.4 

Swine,  Iowa,  live  weight 33. 


406  .   The  Feeding  of  Animals 

Relation  of  food  to  product—  continued 

Produced  by  100  lbs.  digestible  or- 
ganic mattei  in  ration. 
Marketable  Edible 

product  solids 

lbs.  lbs. 

Swine,  general  average,  carcass 25.  15.6 

Pigs,  Iowa,  carcass 25.7  16.1 

Calves,  live  weight 63.7 

Calves,  carcass 36.5  8.1 

Fowl,  large,  live  weight 19.6 

Fowl,  small,  live  weight 19.6 

Fowl,  dressed  carcass,  average 15.6  4.2 

Broilers,  live  weight 28,7 

Broilers,  dressed  carcass 23.8  3.5 

Eggs 19.6  5.1 

It  may  properly  be  said  of  the  foregoing  figures 
that  they  are  only  averages  and  that  the  relation  of 
food  to  production  varies  with  different  animals  of  tlie 
same  class  and  with  the  conditions  involved.  While 
this  is  true,  the  relations  shown  in  the  preceding 
calculations  represent  differences  too  wide  to  be  ex- 
plained on  any  other  ground  than  that  the  various 
animal  products  have  greatly  unlike  food  cost. 

The  most  noticeable  fact  brought  out  by  this  com- 
parison is  the  low  relative  food  cost  of  milk  and  other 
dairy  products.  The  growth  of  a  pound  of  edible 
beef  solids  requires  a  food  expenditure  nearly  seven 
times  as  great  as  is  necessary  for  the  elaboration  of 
a  pound  of  milk  solids.  On  the  other  hand,  swine' 
are  fed  with  nearly  as  great  economy  as  are  milch 
cows.  In  fact,  when  proper  allowance  is  made  for 
the  period  of  growth  of  the  cow  and  for  the  annual 
periods  when  she  is  giving  no  milk,  she  seems  to  have 


Relative  Food   Cost  of  Animal  Products        407 

no  advantage  over  the  pig  except  in  kind  of  product. 
Next  in  the  order  of  economical  use  of  food  conies 
the  calf,  when  fed  largely  on  milk.  Poultry  products 
stand  next  in  line.  Sheep  and  lambs  do  not  differ 
materially  from  steers,  meat  products  of  these  two 
classes  requiring  the  largest  proportional  food  con- 
sumption of  any  form  of  growth  here  considered.  The 
order  of  food  efficiency  as  related  to  the  several  animal 
products  is  therefore  as  follows  :  milk,  pork,  veal, 
poultry  and  eggs,  mutton  and  beef.  The  common 
claims  that  the  food  cost  of  a  pound  of  butter  is  no 
greater  than  that  of  a  pound  of  dressed  carcass  is 
not  borne  out  by  these  average  figures. 

It  is  suggestive,  at  least,  to  notice  that  the  food 
factor  is  inversely  as  the  labor  factor  in  these  various 
lines  of  production.  For  instance,  labor  is  a  large 
factor  of  the  cost  of  a  pound  of  any  dairy  product, 
and  a  small  factor  in  the  cost  of  beef  or  mutton,  while 
the  reverse  is  emphatically  true  of  the  food  cost. 


CHAPTER   XXVII 

GENERAL   MANAGEMENT 

There  are  many  considerations  pertaining  to  the 
feeding  and  management  of  live  stock  that  have  a 
more  or  less  common  application  to  all  classes  of 
animals  and  which  may  be  discnssed  conveniently 
nnder  one  head.  They  are  partly  of  a  bnsiness  char- 
acter and  to  qnite  an  extent  lie  outside  the  chemical 
and  physiological  principles  of  nutrition.  Some  of 
those  questions  are  matters  of  much  importance,  but 
many  of  them  which  relate,  for  instance,  to  times  and 
methods  of  feeding  are  given  a  prominence  in  current 
discussions  out  of  proportion  to  their  real  influence 
in  determining  success.  It  should  be  understood,  too, 
that  many  of  the  details  of  practice  are  not  limitable 
by  fixed  rules  but  must  be  variable  according  to  the 
conditions  involved.  Tact  and  judgment  are  demanded 
of  the  farmer  who  wisely  adjusts  his  practice  to  busi- 
ness principles. 

General  management  properly  includes,  among 
other  considerations,  the  following  topics: 

(1)  The  selection  of  animals;  (2)  manipulation  of 
the  ration  and  manner  of  feeding;  (3)  the  intensity 
of  feeding;  (4)  environment  and  treatment  of  the 
animal. 

(408) 


The  Animal  as  a  Business  Factor  409 

SELECTION     OF     ANIMALS 

The  object  to  be  sought  in  feeding  animals  is  the 
conversion  of  a  unit  of  food  into  the  largest  possible 
quantitj'  of  the  product  best  adapted  to  the  producer's 
commercial  opportunities,  and  here  the  limitations  of 
the  animal  are  often  the  limitation  of  the  farmer's 
profits.  Within  each  species  varietal  and  individual 
differences  determine  the  rate  of  production  and  also 
whether  the  food  shall  be  transformed  into  poor  milk 
or  rich  milk,  inferior  beef  and  mutton  or  superior 
meat  products,  fine  wool  or  coarse,  trotters  or  draft 
horses,  and  small   eggs  or  large  ones. 

The  selection  of  animals  should  have  reference  to 
three  general  factors,  which  largely  fix  the  rate  and 
character  of  production, — viz.,  breed,  individuality 
and  age. 

The  selection  of  cows. — The  breed  and  individuality 
of  the  cow  largelj-  determine  the  quality  of  her  product 
and  the  quantity  of  production  from  a  unit  of  food. 
Neither  heavy  feeding  nor  skill  in  compounding  rations 
can  be  made  the  means  of  causing  her  to  overstep  her 
constitutional  limitations. 

The  selection  of  cows  simply  with  reference  to  breed 
is  a  question  of  adaptability.  If  the  production  of 
milk  at  the  minimum  food  cost  per  unit  of  volume  is 
the  result  most  desired,  the  dairy  breeds  characterized 
by  milk  with  a  low  proportion  of  solids  should  be 
chosen,  but  if  the  object  is  to  merely  secure  butter -fat 
with  the  lowest  possible  food  expenditure,  the  so-called 
butter  breeds  are  iu   general  to  be  preferred. 


410  The  Feeding  of  Animals 

When  the  chief  consideration  is  the  manufacture 
of  milk  solids  most  economicallj-,  we  must  deal  not  so 
much  with  breeds  as  with  individuals.  In  fact,  with 
all  breeds  and  with  animals  of  no  breed,  individual 
capacity  is  the  consideration  fundamental  to  profitable 
feeding.  Some  Holsteins  will  return  both  more  milk 
and  more  butter  for  a  unit  of  food  cost  than  will  some 
Jerseys,  and  the  reverse  is  equally  true.  There  is  no 
magic  in  heredity  which  overcomes  lack  of  capacity 
either  for  the  breeder  or  for  the  dairyman. 

The  "general -purpose"  cow  has  been  much  dis- 
cussed in  recent  years.  While  her  specifications  have 
never  been  fully  and  clearly  set  forth,  it  is  supposed 
that  she  is  an  animal  reasonably  profitable  along*  both 
beef  and  milk  lines.  It  is  doubtful  whether  such  a 
cow,  even  if  she  exists,  is  one  adapted  to  general  utility. 
There  are  few  localities  where  milk  is  not  more  profit- 
able than  beef  or  beef  more  profitable  than  milk,  and 
whichever  is  the  more  profitable  should  be  produced 
by  an  animal  of  specialized  capacity.  Any  extra  value 
which  the  calves'  and  the  cow's  carcass  may  have  when 
flesh-forming  tendencies  are  prominent,  will  generally 
come  far  short  of  compensating  for  a  merely  mediocre 
milk  yield  in  those  localities  where  there  is  a  market 
for  milk  and  its  products;  and  the  stockman  who  is 
endeavoring  to  put  on  the  market  beef  animals  of  the 
highest  quality  cannot  afford  to  compromise  with  dairy 
qualities.  Milk  formation  and  flesh  formation  are  an- 
tagonistic, and  not  correlated,  functions,  both  of  which 
do  not  operate  intensely  in  the  same  individual.  At 
present   we    have    no   breed  or   fixed   type   of   animals 


Animals  for  Meat  Prochidion  411 

that  can  be  regarded  as  presenting  and  perpetuating 
"general -purpose"  qualities.  Such  a  type,  if  found  at 
all,  must  be  sought  among  individuals. 

The  selection  of  animals  for  meat  production. — It  is 
generally  conceded  that  the  selection  of  breeds  of  the 
beef  and  mutton  types  is  essential  to  the  highest  suc- 
cess in  the  production  of  meat.  This  is  true  with 
steers,  not  because  those  from  the  dairy  breeds  will 
make  very  much  slower  growth  thau  Shorthorns  or 
Herefords,  for  this  does  not  seem  to  be  the  fact,  but 
because  the  quality  of  the  product  is  higher  with  the 
latter,  that  is,  the  proportion  of  valuable  parts  is 
greater  and  the  distribution  of  fat  and  lean  tissue  is 
more  desirable,  in  the  distinctly  beef  animal. 

A  choice  from  the  beef  and  mutton  tj'pes  and  from 
the  various  breeds  of  swine  may  safely  be  left  to  per- 
sonal preference.  Many  experiments  have  been  con- 
ducted with  a  view  of  determining  the  relative  capacity 
of  growth  of  the  prominent  breeds  of  bo  vines,  sheep, 
and  swine,  and  the  testimony  so  far  adduced  is  of  a 
negative  character  and  does  not  point  to  any  one  breed 
of  any  species  as  clearly  superior  to  all  others.  It  is 
well  understood,  however,  that  within  every  breed  in- 
dividual variations  are  important  and  that  from  a 
"bunch"  of  steers  it  is  possible  to  select  some  animals 
superior  to  the  others  in  their  capacity  to  make  profit- 
able use  of  food. 

A  most  important  factor  in  this  connection  is  the 
relation  of  age  to  the  profits  of  meat  production. 
Nothing  has  been  more  fully  established  by  experi- 
mental   evidence    than    that   the   vounerer   the    animals 


412  The  Feeding  of  Animals 

the  larger  the  ratio  of  increase  to  body  weight  and  the 
greater  the  increase  for  each  unit  of  food  consumed. 

Some  of  the  more  striking  evidence  on  these  points 
is  presented  in  the  following  figures: 

Results  tcith  steers  from  five  breeds  slaughtered  at  the  SmithfuJd 
{England)  Fat- Stock  Show  [from  Henry^s  compilation) 

Age  Number  animals  Daily  gain 

One  year  old  77  2.00  lbs. 

Two  years  old  89  1.76    '' 

Three  years  old  54  1.58    " 

Steers  at  American  Fat- Stock  Sho70  {StewarVs  compilation) 

Age  Number  animals  Daily  gain 

297  days  30  2.6  lbs. 

612     "  152  2.2     " 

943     "  145  1.7    " 

1,283     "  133  1.5    " 

American  experiments  with  pigs    { Henry ^s  compilation) 

Weight  of  pigs  Number  feeding  trials        Food  for  100  lbs.  gain  ' 

38  lbs.  41  293  lbs.     . 

78    *'  100  400    " 

128    "  119  437    " 

174     ''  107  482    " 

227    "  72  498    " 

271     "  46  511     *• 

320     "  19  535    " 

Results  of  Danish  experiments  with  pigs 

Weight  of  pigs  Number  experiments  Food  for  100  lbs.  gain 

35  to    75  lbs.  3  376  lbs. 

75  to  115    ''  .             10  435    " 

115  to  135    ''  13  466    " 

155  to  195    "  15  513    " 

195  to  235    '*  14  540    " 

235  to  275    "  11  614    " 

275  to  315    "  3  639    " 


Treatment  of  Ration  413 

Testimoii}'  of  this  character  is  abundant,  and  the 
lesson  for  practice  is  that  animals  should  be  fed  for 
market  at  the  earliest  age  that  is  consistent  with  other 
conditions. 

MANIPULATION     OF     THE     RATION 

A  great  deal  of  experiment  and  discussion  has  been 
devoted  to  the  economy  of  various  methods  of  treating 
cattle  foods,  such  as  cutting,  grinding,  wetting  and 
cooking.  The  economy  of  these  operations  requires  no 
extended  comment.  It  is  a  simple  and  safe  rule  that 
any  fodder  or  grain  that  in  its  natural  condition  is 
palatable,  is  wholly  eaten  and  is  thoroughly  masticated, 
should  be  fed  without  the  unnecessary  expense  which 
these  manipulations  would  cause.  Grinding  any  mate- 
rial that  is  not  otherwise  thoroughly  masticated  doubt- 
less increases  the  efficiency  of  the  food,  but  when  the 
grinding  costs  as  much  as  10  per  cent  of  the  market 
price  of  the  grain  it  is  doubtful  if  any  advantage 
accrues.  Cutting,  unless  for  the  purpose  of  mixing, 
has  the  sole  advantage  of  saving  the  animal  a  little 
work. 

Wetting  and  cooking  render  certain  foods  more 
tender  and  more  palatable,  and  when  this  secures  the* 
consumption  of  materials  otherwise  wasted  these  opera- 
tions may  become  economical.  On  the  contrary,  simi- 
lar treatment  of  grain  foods  alread}'  much  liked  by  the 
animal  is,  according  to  the  majority  of  testimonj',  an 
occasion  of  loss  rather  than  of  gain. 

Practice  differs  as  to  the  number  of  portions  into 
which  the  daily  ration  shall  be  divided.     Some   herds 


414  The  Feeding  of  Animals 

are  fed  three  times  a  day  and  some  twice.  While  it 
would  be  possible  to  feed  too  many  times,  or  too 
much  at  any  one  time,  it  seems  more  than  probable 
that  if  animals  are  fed  regularly  the  ration  may  be 
as  efficient  when  divided  into  two  portions  as  when 
there  are  three  feeding  periods.  The  adaptation  of 
anj'  system  to  the  requirements  of  farm  work  is  a 
matter  of  more  importance,  probably,  than  any  in- 
fluences proceeding  from  the  number  of  feeding  periods. 
The  warming  of  the  water  consumed  has  been  intro- 
duced to  some  extent  with  dairy  herds.  Certainly  it  is 
bad  practice  to  force  cows  to  drink  ice-cold  water,  but 
it  is  also  bad  practice  to  warm  the  water  above  the 
point  of  palatableness.  The  likes  and  dislikes  of 
animals  must  be  considered,  and  to  ignore  them,  even 
to  save  the  small  food  expense  necessary  for  warming 
the  ingested  water,  is  not  advisable. 

QUANTITY    OF    THE     RATION 

Great  stress  is  usually  laid  upon  the  fact  that  it 
is  only  the  food  that  is  supplied  above  maintenance 
needs  which  is  productive.  This  truth,  indiscrimi- 
nately accepted,  has  led,  the  writer  believes,  to  feed- 
ing so  excessively  as  to  injure  the  health  of  the 
animals  and  diminish  profits.  The  largest  production 
is  not  always  the  most  profitable.  Abundant  testimony 
can  be  cited  in  support  of  the  statement  that  very 
heavy  rations  yield  smaller  returns  per  unit  of  food 
consumed  than  more  moderate  ones.  It  is  possible, 
also,  to  adopt  an  unprofitable  extreme  in  the  direction  of 


Quantity  of  Ration  —  Management  415 

light  feeding.  Heavy  rations  are  sometimes  warranted 
by  the  low  cost  of  feeds  and  the  high  price  of  the  resnlt- 
ing  product,  a  condition  which  has  not  existed  for 
the  past  ten  years.  In  the  writer's  judgment  milk  is 
more  economically  produced  by  cows  not  unusual  in 
character  or  size  when  the  grain  ration,  wisely  com- 
pounded, ranges  between  8  and  12  pounds  daily, 
according  to  the  weight  and  capacity  of  the  animal, 
than  when  more  is  fed,  provided  the  coarse  foods  are 
supplied  in  the  ordinary  proportion.  It  is  especially 
important  with  breeding  animals,  where  the  physical 
condition  of  the  dam  should  be  kept  at  its  best,  that 
the  indigestion  and  high  physical  tension  induced  by 
extreme  rations  should  be  avoided. 

ENVIRONMENT    AND    TREATMENT     OF    ANIMALS 

The  quarters  in  which  animals  live  should  be  com- 
fortable, that  is,  they  should  be  neither  too  warm  nor 
too  cold  and  should  be  well  ventilated.  These  condi- 
tions are  essential  to  health  and  the  most  profitable 
production.  The  stable  temperature  in  winter  should 
be  held  above  45°  F.  as  a  minimum,  and  may  well  be 
kept  below  60°.  A  constant  exchange  of  air  should  be 
secured  without  creating  cold  drafts,  and  the  "King" 
system  of  ventilation  seems  to  be  worthy  of  com- 
mendation. 

All  domestic  animals,  whether  the  milch  cow  or  the 
fattening  steer,  should  have  a  reasonable  amount  of 
exercise  under  comfortable  conditions.  Little  sym- 
pathy  should   be    shown   towards   the    modern   fad   of 


416  The  Feeding  of  Animals 

tying  cows  b}^  their  licMds  in  one  spot  for  five  or  six 
months,  nnder  the  plea  that  exercise  is  work  and  work 
costs  food.  The  statement  had  better  be  in  accord- 
ance with  the  experience  of  all  time,  that  exercise  is 
health  and  vigor  and  that  food  is  well  used  in  main- 
taining these.  The  cow  is  more  than  a  machine;  she 
is  a  sentient  being,  susceptible  to  many  of  the  influ- 
ences which  are  essential  to  the  physical  welfare  of 
the  human  species.  Let  no  one  take  this  opinion  as 
an  excuse  for  the  cruel  and  wastefnl  exposure  of 
farm  animals  to  inclement  weather,  which  is  so  often 
observed,  for  this  is  simply  a  violation  of  the  laws  of 
kindness  and  economy  in  the  other  direction. 

A  sympathetic  relation  should  be  established  be- 
tween the  animal  and  the  herdsman.  Close  observers 
declare  that  such  a  relation  promotes  greater  thrift 
and  larger  production,  especially  with  dairy  cows. 
These  animals,  possessed  of  the  instincts  and  affec- 
tions of  motherhood,  respond  to  fondling  through  its 
influence  upon  their  nervous  organization. 

Moreover,  the  economic  relation  is  not  the  only  one 
man  sustains  to  the  animal  world.  Farm  animals  are 
man's  companions  and  friends,  for  which  he  may  enter- 
tain even  sentiments  of  affection.  The  daily  life  of  the 
farm-house  is  full  of  pleasant  experiences  that  belong  to 
the  care  of,  and  association  with,  the  grateful  creatures 
whose  wants  must  be  supplied, — the  motherly  cow,  the 
faithful  horse  or  the  nois}^  cackling  fowl.  No  farmer 
has  reached  his  best  estate  who  does  not  find  in  the 
animal  life  about  him  an  enjoyable  companionship  of 
which   he  need  not   be   ashamed,  and  without  a  sense 


Kindness  toward  Animals  417 

of  which  he  is  not  prepared  to  talfil  his  obligations  to 
the  creatures  dependent  upon  him. 

While  it  is  the  purpose  of  this  volume  to  deal  with 
the  facts  and  principles  of  science  and  practice,  it  is 
not  improper  to  briefly  urge  the  need  of  the  cultivation 
of  right  sentiment  concerning  kindness  in  the  care  of 
animals,  for  w^e  really  do  not  fully  appreciate  the  unkind- 
ness  shown  by  man  toward  the  inferior  species  under 
his  control.  In  no  way  has  he  more  clearly  demon- 
strated that  he  partakes  of  the  brute  nature  than  in 
his  treatment  of  the  brute.  As  a  master  he  has  been 
guilty  of  cruelty  which  it  is  humiliating  to  contemplate, 
a  cruelty  not  as  swift  in  its  operation  as  that  of  the 
beast  of  prey,  but  which  is  greatly  more  shocking  and 
is  wholly  at  variance  with  the  exalted  characteristics 
tliat  we  attribute  to  humanity.  The  half -sheltered  ani- 
mals that  have  endured  our  cold  northern  winters,  the 
spavined,  wind -broken  wrecks  of  our  livery  stables, 
whose  infirmities  secure  for  them  no  relief  from  hard 
service,  the  daily  exhibitions  on  our  city  streets  of  the 
patient  draft  horse  with  raw  flesh  under  the  collar  and 
smarting  under  blows  from  unfeeling,  cursing  drivers, 
and  especially  the.  deliberately  brutal  practices  of  the 
race- track,  w^here  amid  the  plaudits  of  a  throng  of  men 
and  women  who  w^ould  claim  to  have  kind  hearts,  noble 
animals,  by  unjustifiable  "scoring"  and  in  the  subse- 
quent race,  are  often  forced  to  the  last  limits  of  en- 
durance, are  all  evidences  of  an  utterly  selfish  indiffer- 
ence to  the  suffering  of  living  creatures  that  can  neither 
utter  a  complaint  nor  avenge  their  wrongs.  A  certain 
proportion  of  humanity  appears   to  regard  the  animal 

AA 


418  The  Feeding  of  Animals 

as  a  mere  unfeeling  machine  out  of  which  pleasure  and 
gain  are  to  be  forced  even  to  the  pound  of  flesh,  and 
not  as  sentient  beings  capable  of  the  keenest  physical 
pain  and  with  rights  that  should  be  respected.  The 
constant  occurrence  of  the  ill-treatment  of  animals  is 
perhaps  the  cause  of  the  complaisance  with  which  it  is 
regarded,  but  it  is  no  excuse  for  such  thoughtless  indif- 
ference. Society  notes  and  punishes  flagrant  cases  of 
abuse,  but  the  average  human  conscience  is  not  yet 
sufficiently  tender  toward  man's  treatment  of  his  faith- 
ful servants. 


APPENDIX 

COMFOSIIION  AND   DIGESTION  TABLES 

1.  Average  composition  of  American  feeding  stuffs 

(pp.  419-427). 

2.  Average  coefficients  of  digestion  (pp.  427-435). 

3.  Feeding  standards  (pp.  435-438). 

4.  Fertilizing  constituents  of  American  feeding  stuffs 

(pp.  439-443). 

1.    AVERAGE    COMPOSITION   OF   AMERICAN 
FEEDING  STUFFS 

The  figures  in  the  following  table  have  been  taken 
from  Bulletin  No.  11,  Office  of  Experiment  Stations  ; 
Farmers'  Bulletin  No.  22,  U.  S.  Department  of  Agricul- 
ture; Henry's  Feeds  and  Feeding,  Bulletin  No.  81,  Ver- 
mont Agricultural  Experiment  Station,  and  Bulletin  No. 
1G6,  New  York  State  Agricultural  Experiment  Station. 

The  percentages  given  represent  averages  from  which 
there  are  material  variations.  These  variations  are 
mostly  due  to  differences  in  the  water  content,  the  in- 
fluence of  locality  and  of  the  stage  of  growth  and  the 
changes  brought  about  by  the  methods  and  conditions 
of  curing.  They  are  not  as  large  and  important  with 
the  grains  as  with  the  fodders. 

(419) 


420 


Appendix 


Composition,  of  Feeding   Stuffs 


cut 


Water 


Green  Fodder 
Cora  fodder —  * 

Flint  varieties  ...    79.8        1.1 
Flint    varieties    cut 
after  kernels  had 

glazed  

Dent  varieties  .    .    . 

Dent   varieties    cut 

after  kernels  had 

glazed      

Sweet  varieties  .  . 
All  varieties  .... 
Leaves    and    husks, 

cut  green   . 
Stripped    stalk 
green      .    . 
Sorghum  fodder  . 
Kye  fodder    .    . 
Barley  fodder  . 
Oat  fodder     .    . 
Pasture  grass    . 
Redtop,t  in  bloom    . 
Tall    oat    grass, t    in 
bloom     .... 
Orchard    grass,     in 

bloom 
Meadow   fescue,    in 

bloom 69.9        1.8 

Italian  rye  grass,  com- 
ing into  bloom     .    73.2       2.5 
Timothy,?  at  different 

stages 61.6       2.1 


Nitrogen- 

No.  of 

free  ex- 

aiKily- 

Ash 

Proteiu 

Fiber       trtict 

Fat       ses 

% 

% 

%             % 

% 

77.1 
79. 


73.4 
79.1 
79.3 

66.2 

76.1 

79.4 

76.6 

79. 

62.2 

80. 

65.3 

69.5 

73. 


1  1 
1.2 

1.5 
1.3 
1.2 

2.9 

.7 
1.1 
1.8 
1.8 
2.5 
2. 
2.3 


*Corn  fodder  is  the  entire  plant,  usually 
is  what  is  left  after  the  ears  are  harvested, 
t  Herd's  grass  of  Pennsylvania. 
§  Herd's  grass  of  New  England  and  New 


2. 

2.1 
1.7 

2. 

1.9 

1.8 

2.1 

.5 
1.3 
2.6 
2.7 
3.4 
3.5 
2.8 

2.4 

2.6 

2.4 

3.1 

3.1 

a  thicl. 

York. 


4.3  12.1 

4.3  14.6 

5.6  12. 

6.7  15.5 

4.4  12.8 

5.0  V2.'l 

8.7  19. 

7.3  14.9 

6.1  11.6 
11.6  6.8 

7.9  8. 

11.2  19.3 

4.  9.7 

11.  17.7 

9.4  15.8 

8.2  13.3 
10.8  14.3 

6.8  13.3 


.9 
.5 
.5 

1.1 

.5 
.5 
.6 
.6. 
1.4 
.8 
.9 

.9 

.9 


1.3 


11.8      20.2        1.2 

;ly  planted  crop.     Corn 

t  Meadow  Oat  Grass. 


40 


10 
63 


7 

21 

126 


3 

4 

4 

24. 

56 

itover 


Composition  of  Feeding  Stuffs 


421 


Nitrogen 

No.  of 

free  ex- 

analy- 

Water 

Ash 

Protein 

Fiber 

tract 

Fat 

ses 

% 

% 

% 

% 

% 

% 

Greeyi  Fodder—  continued 

Kentucky  blue  grass,* 

at  different  stages 

65.1 

2.8 

4.1 

9.1 

17.6 

1.3 

18 

Hungarian  grass  .    .    . 

71.1 

1.7 

3.1 

9.2 

14.2 

.7 

14 

Japanese  millet    .    .    . 

75. 

1.5 

2.1 

7.8 

13.1 

.5 

12 

Red  clover,  at  differ- 

ent stages  .... 

70.8 

2.1 

4.4 

8.1 

13.5 

1.1 

43 

Alsike    clover,!    in 

bloom 

74.8 

2. 

3.9 

7.4 

11. 

.9 

4 

Crimson  clover     ,    .    . 

80.9 

1.7 

3.1 

5.2 

8.4 

.  i 

3 

Alfalfa, t  at  different 

stages 

71.8 

2.7 

4.8 

7.4 

12.3 

1. 

23 

Serradella,   at  differ- 

ent stages  .... 

79.5 

3.2 

2.7 

5.4 

8.6 

.7 

9 

Cowpea          

83. G 

1.7 

2.4 

4.8 

7.1 

.4 

10 

Soja  bean 

75.1 

2.G 

4. 

6.7 

10.6 

1. 

27 

Horse  bean    .... 

84.2 

1.2 

2.8 

4.9 

6.5 

0.4 

2 

Flat   pea    {Laihijrus 

sylvestris)  .... 

GG.7 

2.9 

8.7 

7.9 

12.2 

1.6 

2 

Rape 

84.5 

2. 

2.3 

2.6 

8.4 

.5 

2 

Silage 

Corn  silage    .... 

79.1 

1.4 

1.7 

6. 

11. 

.8 

99 

Sorghum  silage    .    . 

7G.1 

1.1 

.8 

G.4 

15.3 

.3 

6 

Red  clover  silage     . 

72. 

2.6 

4.2 

8.4 

11.6 

1.2 

5 

Soja  bean  silage  .    . 

74.2 

2.8 

4.1 

9.7 

6.9 

9  ^ 

1 

Cowpea  vine  silage. 

79.3 

2  9 

2.7 

6. 

7.6 

1.5 

2 

Field  pea  vine  silage 

50.1 

3.5 

5.9 

13. 

26. 

1.6 

1 

Silage  of  mixture  of 

cowpea  vines  and 

soja  bean  vines    . 

69.8 

4.5 

3.8 

9.5 

11.1 

1.3 

1 

Millet  and  soja  bean 

79. 

2.8 

2.8 

7.2 

7.2 

1. 

9 

Corn   and    soja    bean 

76. 

2.4 

2.5 

7.2 

11.1 

.8 

4 

Rye 

80.8 

1.6 

2.4 

5.8 

9.2 

.3 

1 

Apple  pomace  .... 

85. 

.6 

1.2 

3.3 

8.8 

1.1 

1 

*June  Grass. 

tSwedish  Clover. 

tLucerne. 

422  Appendix 


1 


Nitrogen-  No.  ot 

free  ex-  ;ui;ily- 

Water     Ash     Protein    Fiber       tract        Fat       ses 
%  %  %  %  %  % 

Hay  and  Dry  Coarse  Fodder 

Corn    fodder,*   field - 

cured 42.2 

Corn    leaves,     field - 

cured 30. 

Corn     husks,     field- 
cured  50.9 

Corn    stalks,      field - 

cured G8.4 

Corn    stovert     field- 
cured  40.5 

Barley    hay,    cut    in 

milk 15. 

Oat  hay,  cut  in  milk    15. 
Hay  from — 

Redtop,t  cut  at  dif- 
ferent stages     .    .      8.9 
Redtop,  cut  in  bloom      8.7 
Orchard  grass    ...      9.9 
Timothy, g  all  analy's   13.2       4.4 
Timothy,  cut  in  full 

bloom 15. 

Timothy, cut  soon  af- 
ter bloom   ....    14.2 
Timothy,  cut  when 

nearly  ripe  .  .  .  14.1 
Kentucky  blue  grass  21.2 
Cut  when  seed  was 

in  milk    .        ...    24.4        7.  6.3      24.5      34.2        3.C 

Cut  when  seed  was 

ripe      27.8 

Hungarian  grass  .    .      7.7 
Meadow  fescue     .    .    20. 
Italian  rye  grass  .    .      85 

*  Entire  plant. 

tWhat  is  left  after  the  ears  are  harvested. 

t  Herd's  grass  of  Pennsylvania. 

'i  Herd's  grass  of  New  England  and  New  York. 


2.7 

4.5 

14.3 

34.7 

1.6 

35 

5.5 

G. 

21.4 

35.7 

1.4 

17 

1.8 

2.5 

15.8 

28.3 

.7 

16 

1.2 

1.9 

11. 

17. 

.5 

15 

3.4 

3.8 

19.7 

31.5 

1.1 

GO 

4.2 

8.8 

24.7 

44.9 

2.4 

1 

5.2 

9.3 

29.2 

39. 

2.3 

1 

5.2 

7.9 

28.6 

47.5 

1.9 

9 

4.9 

8. 

29.9 

46.4 

2.1 

3 

6. 

8.1 

32.4 

41. 

2.6 

10 

4.4 

5.9 

29. 

45. 

2.5 

68 

4.5 

6. 

29.6 

41.9 

3. 

12 

4.4 

5.7 

28.1 

44.6 

3. 

11 

3.9 

5. 

31.1 

43.7 

2.2 

12 

G.3 

7.8 

23. 

37.8 

3.9 

10 

6.4 

5.8 

23.8 

33.2 

3. 

4 

6. 

7.5 

27.7 

49. 

2.1 

13 

6.8 

7. 

25.9 

38.4 

o  r 

9 

6.9 

7.5 

30.5 

45. 

1.7 

4 

Composition  of  Feeding  Shtffs 


423 


Water 

Ash 

Protein 

Fiber 

Nitrogen- 
free  ex- 
tract 

Fat 

No.  of 
analy- 
ses 

% 

Hay  and  Dry  Coarse  Fodder 
— contiuued 

% 

^\ 

% 

% 

% 

Hay  from— 

Perennial  rye  grass 

.     14. 

7.9 

10.1 

25.4 

40.5 

1.7 

4 

Mixed  grasses   .    . 

.     15.3 

5.5 

7.4 

27.2 

42.1 

2.5 

126 

Rowen  (mixed)*  . 

16.6 

6.8 

11.6 

22.5 

39.4 

3.1 

23 

Mixed    grasses    anc 
clovers    .... 

.    12.9 

5.5 

10.1 

27.6 

41.3 

2.6 

17 

Swamp  hay    .    .    . 

.    11.6 

6.7 

7.2 

26.6 

45.9 

2. 

8 

Salt  marsh     .    ,    . 

.    10.4 

7.7 

5.5 

30. 

44.1 

2.4 

10 

Red  clover     .    .    . 

.    15.3 

6.2 

12.3 

24.8 

38.1 

3.3 

38 

Red  clover  in  bloon 

I    20.8 

6.6 

12.4 

21.9 

33.8 

4.5 

6 

Alsike  clover    .    . 

9.7 

8.3 

12.8 

25.6 

40.7 

2.9 

9 

White  clover     .    . 

9.7 

8.3 

15.7 

24.1 

39.3 

2.9 

7 

Crimson  clover     . 

9.6 

8.6 

15.2 

27.2 

36.6 

2.8 

7 

Japan  clover     .    . 

.    11. 

8.5 

13.8 

24. 

39. 

3.7 

2 

Vetch 

.    11.3 

7.9 

17. 

25.4 

36.1 

2.3 

5 

Serradella     .    .    . 

9.2 

7.2 

15.2 

21.6 

4i.2 

2.6 

3 

Alfalfat      .... 

8.4 

7.4 

14.3 

25. 

42.7 

2.2 

21 

Cow  pea    

10.7 

7.5 

16.6 

20.1 

42.2 

2.2 

8 

Soja  bean  .... 

11.3 

7.2 

15.4 

22.3 

38.6 

5.2 

6 

Flat  pea   (Latliyrus 
sylvestris)  .... 

8.4 

7.9 

22.9 

26.2 

31.4 

3.2 

5 

Peanut  vines  (with- 
out nuts)   .    .    . 

7.6 

10.8 

10.7 

23.6 

42.7 

4.6 

6 

Pea  vines  .... 

15. 

6.7 

13.7 

24.7 

37.6 

2.3 

1 

Soja -bean  straw  .    . 

10.1 

5.8 

4.6 

40.4 

37.4 

1.7 

4 

Horse-bean  straw  . 

9.2 

8.7 

8.S 

37.6 

34.3 

1.4 

1 

Wheat  straw     .    .    . 

9.6 

4.2 

3.4 

38.1 

43.4 

1.3 

7 

Rye  straw      ,    .    .    . 

7.1 

3.2 

3. 

38.9 

46.6 

1.2 

7 

Oat  straw 

9.2 

5.1 

4. 

37. 

42.4 

2.3 

12 

Buckwheat  straw     . 

9.9 

5.5 

5.2 

43. 

35.1 

1.3 

3 

Foots  and  Tubers 

Potatoes 

78.9 

1. 

2.1 

.6 

17.3 

.1 

12 

Sweet  potatoes     .    . 

71.1 

1. 

1.5 

1.3 

24.7 

.4 

6 

*  Second 

cut. 

tLuceme. 

424 


Appendix 


Nitroge 

n- 

No.  of 

free  ex 

analy- 

Water 

Ash 

Protein 

Fiber 

traet 

Fat 

ses 

% 

% 

% 

% 

% 

% 

Foots  a7id  Tubers— eonVd 

Red  beets 

88.5 

1. 

1.5 

.9 

s. 

.1 

9 

Sugar  beets 

8C.5 

.9 

1.8 

.9 

9.8 

.1 

19 

Mangel -wurzels  .    .    . 

90.9 

1.1 

1.4 

.9 

5.5 

.2 

9 

Turnips  .... 

90.5 

.8 

1.1 

1.2 

6.2 

.2 

3 

Rutabagas 

88.6 

1.2 

1.2 

1.3 

7.5 

.2 

4 

Carrots 

88.6 

1. 

1.1 

1.3 

7.6 

.4 

8 

Artichokes 

79.5 

1. 

2.6 

.8 

15.9 

.2 

2 

Grains  and  Other  Seeds 

Corn  kernel — 

Dent,  all  analyses   . 

10.6 

1.5 

10.3 

2.2 

70.4 

5. 

86 

Flint,  all  analyses  . 

11.3 

1.4 

10.5 

1.7 

70.1 

5. 

6S 

Sweet,  all  analyses. 

8.8 

1.9 

11.6 

2.8 

66.8 

8.1 

2() 

Pop  varieties    .    .    . 

10.7 

l.f) 

11.2 

1.8 

69.6 

5.2 

4 

Soft  varieties    .    .    . 

9.3 

1.6 

11.4 

o 

70.2 

5.5 

5 

All    varieties    and 

analyses     .... 

10.9 

1.5 

10.5 

2.1 

69.6 

5.4 

208 

Sorghum  seed  .... 

12.8 

2.1 

9.1 

2.6 

69.8 

3.6 

10 

Barley 

10.9 

2.4 

12.4 

2.7 

69.8 

1.8 

10 

Oats 

11. 

3. 

11.8 

9.5 

59.7 

5. 

30 

Rye 

11.6 

1.9 

10.6 

1.7 

72.5 

1.7 

6 

Wheat- 

Spring  varieties 

10.4 

1.9 

12.5 

1.8 

71.2 

2.2 

13 

Wintervarieties,  all 

analyses     .... 

10.5 

1.8 

11.8 

1.8 

72. 

2.1 

262 

All  varieties     .    .    . 

10.5 

1.8 

11.9 

1.8 

71.9 

2.1 

310 

Rice 

12.4 

.4 

7.4 

.2 

79.2 

.4 

10 

Buckwheat 

12.6 

2. 

10. 

8.7 

64.5 

2.2 

8 

Sunflower  seed '  whole) 

8.6 

2.6 

16.3 

29.9 

21.4 

21.2 

2 

Flaxseed    

9.2 

4.3 

22.6 

7.1 

23.2 

33.7 

50 

Cottonseed  (whole. 

with  hulls)    .    .    . 

10.3 

3.5 

18.4 

23.2 

24.7 

19.9 

5 

Cottonseed  kernels 

(without  hulls)    . 

6.2 

4.7 

31.2 

3.7 

17.6 

36.6 

o 

Cottonseed     whole, 

roasted    .... 

6.1 

5.5 

16.8 

20.4 

23.5 

27.7 

2 

Composition  of  Feeding  Stnffs  425 


Water  Ash  Protein  Fiber 

%  %  %  % 
Grains  and  Other  Seeds — 
continued 

Peanut  kernel  (with- 
out hulls)  ....  7.5  2.4  27.9  7. 
Horse  bean    .    .       .    .  11.3  3.8  26.6  7.2 

Soja  bean 10.8  4.7  34.  4.8 

Cowpea 14.8  3.2  20.8  4.1 

Mill  Products 

Corn  meal 15.  1.4  9.2  1.9 

Corn  and  cob  meal  .    .  15.1  1.5  8.5  6.6 

Oatmeal 7.9  2.  14.7  .9 

Barley  meal 11.9  2.6  10.5  6.5 

Rye  flour 13.1  .7  6.7  .4 

Wheat  flour,allanaly's  12.4  .5  10.8  .2 

Buckwheat  flour  .    .    .  14.6  1.  6.9  .3 

Ground  linseed     .    .  8.1  4.7  21.6  7.3 

Pea  meal 10.5  2.6  20.2  14.4 

Soja-bean  meal    .    .    .  10.8  4.5  30.7  4.5 
Ground  corn  and  oats 

equal  parts    ...  13.  2.2  10.5  5.7      64.2       4.4 

Waste  Products 

Corncob 10.7  1.4  2.4  30.1 

Hominy  chops  .    .    .    .  11.1  2.5  9.8  3.8 

Corn  bran 9.1  1.3  9.  12.7 

Corn  germ 10.7  4.  9.8  4.1 

Corn -germ  meal  .    .    .  8.1  1.3  11.1  9.9 
Gluten  meal — 

Cream 10.1  .8  33.7  1.7 

Chicago* 12.3  1.3  36.5  1.4 

King 7.4  .5  33.7  1.2 

Gluten  feed 7.8  1.1  24.  5.3 

Buffalo* 9.6  2.3  27.1  6.7 

Peoria* 7.5  .8  19.8  8.2 

Diamond,  or  Roek- 

ford 8.9  .8  23.6  6.6      56.6        3.5 

*Inehided  in  above  average. 


^itroger 
free  ex- 
tract 

% 

- 

Fat 

% 

No.  of 
analj- 

15.6 

39.6 

7 

50.1 

1. 

1 

28.8 

16.9 

8 

55.7 

1.4 

5 

68.7 

3.8 

77 

64.8 

3.5 

7 

67.4 

7.1 

6 

66.3 

2.2 

3 

78.3 

.8 

4 

75. 

1.1 

20 

75.8 

1.4 

4 

27.9 

30.4 

2 

51.1 

1.2 

2 

27.3 

16.2 

1 

54.9 

.5 

18 

64.5 

8.3 

12 

62.2 

5.8 

5 

64. 

7.4 

3 

62.5 

7.1 

6 

51.1 

2.6 

45.8 

2.7 

.    . 

52.6 

4.6 

.    . 

51.2 

10.6 

11 

51.1 

3.2 

51.1 

12.6 

1 

426 


Appendix 


Water     Ash     Protein    Fiber 


Waste  Produces— continued 
Chicago  maize  feed    .  9.1 
Glucose  feed  and  glu- 
cose refuse    .    .    .  C.5 
Dried  starch  feed  and 

sugar  feed     .    .    .  10.9 

Starch  feed,  wet  .    .    .  G5.4 

Oat  hulls 7.3 

Oat  feed 7.7 

Barley  screenings    .    .  12.2 

Malt  sprouts     ....  5. 

Brewers'  grains,  wet  .  75.7 

Brewers' grains,  dried  8.2 

Grano  gluten    ....  5.8 

Rye  bran 11.6 

Rye  shorts 9.3 

Wheat    bran     from 

spring  wheat     .    .  11.5 
Wheat     bran     from 

winter  wheat     .    .  12.3 

Wheat  bran,  all  an'ses  11.9 

Wheat  middlings      .    .  10. 

Wheat  shorts     .    .    .    .  11.8 

Wheat  screenings    .    .  11.6 

Rice  bran 9.7 

Rice  hulls 8.2 

Rice  polish 10. 

Buckwheat  hulls  .    .    .  13.2 

Buckwheat  bran  ...  10.5 

Buckwheat    middlings  13.2 

Cottonseed  meal       .    .  fi.S 

Cottonseed  hulls       .    .  11.1 

Lins'd  meal,  old  proc's  8.3 
Lins'd meal,  new proc's  10. 

Peanut  meal  ....  10.7 

Peanut  hulls     ....  9. 


Nitrogen- 
free  ex- 
tract 


Pat 


No.  of 
analy- 
ses 


.9      22.8 


7.6 


5.4      16.1 


6.9 


1.1      20.7        4.5      56.8      10.4 


.9 

19.7 

4.7 

54.8 

9. 

4 

.3 

6.1 

3.1 

22. 

3.1 

12 

6.7 

3.3 

29.7 

52.1 

1. 

3.7 

16. 

6.1 

59.4 

7.1 

4 

3.6 

12.3 

7.3 

61.8 

2.8 

2 

6.4 

27.6 

10.9 

47.1 

3. 

1. 

5.4 

3.8 

12.5 

1.6 

15 

3.6 

19.9 

11. 

51.7 

5.6 

3 

2.8 

31.1 

12. 

33.4 

14.9 

1 

3.6 

14.7 

3.5 

63.8 

2.8 

7 

5.9 

18. 

5.1 

59.9 

2.8 

1 

54.5        4.5      10 


5.9 

16. 

8.1 

53.7 

4. 

7 

5.8 

15.4 

9. 

53.9 

4. 

88 

3.8 

17.4 

5.2 

58. 

5.6 

4.6 

14.9 

7.4 

56.8 

4.5 

12 

2.9 

12.5 

4.9 

65.1 

3. 

10 

10. 

l_.l 

9.5 

49.9 

8.8 

5 

13.2 

3.6 

35.7 

38.6 

.7 

3 

6.7 

11.7 

6.3 

58. 

7.3 

4 

2.2 

4.6 

43.5 

35.3 

1.1 

2 

3. 

12.4 

31.9 

38.8 

3.3 

2 

4.8 

28.9 

4.1 

41.9 

7.1 

3 

62 

45.6 

5.4 

25.2 

10.8 

2.8 

4.2 

46.3 

33.4 

2.2 

20 

5.3 

35.7 

7.5 

36. 

7.2 

5.2 

36.1 

8.4 

36.7 

3.6 

.    , 

4.9 

47.6 

5.1 

23.7 

8.     2 

,480 

3.4 

6.6 

64.3 

15.1 

1.6 

5 

BigestiMlity  of  Feeding  Stuffs 


427 


Water 

Ash 

Protein 

Fiber 

Nitrogen- 
free  ex- 
tract 

Fat 

No.  of 
analy- 

Miscellaneous 

% 

% 

% 

% 

% 

% 

Aeorns 

.    55.3 

1. 

2.5 

4.4 

34.8 

1.9 

.     . 

Apples 

.    80.8 

.'i. 

.7 

1.2 

16.6 

.4 

.     . 

Apple  pomace  .    .    . 

.    76.7 

.5 

1.4 

3.9 

16.2 

1.3 

7 

Beet  pulp 

.    89.8 

.6 

.9 

2.4 

6.3 

16 

Beet  molasses  .    .    . 

.    20.8 

10.6 

9.U 

')    •    • 

59.5 

.    . 

35 

Cabbage     

.    90.5 

1.4 

2.4 

1.5 

3.9 

.4 

2 

Prickly  comfrey 

.    88.4 

2.2 

2.4 

1.6 

5.1 

.3 

41 

Pumpkin  (field)  .    . 

.    90.9 

.5 

1.3 

1.7 

5.2 

.4 

Sugar  beet  leaves    . 

.    88. 

2.4 

2.6 

2.2 

4.4 

.4 

.    . 

2.    AVERAGE   COEFFICIENTS    OF  DIGESTION 

The  coefficients  of  digestion  which  follow  are  mostly 
taken  from  the  compilation  by  Jordan  and  Hall  as  pub- 
lished in  Bulletin  No.  77,  Office  of  Experiment  Stations. 
Others,  marked  G,  are  from  the  compilation  of  Dietrich 
and  Konig  (Composition  and  Digestibility  of  Cattle 
Foods,  Vol.  II). 

Digestion   by  Ruminants 


No.  ex-        Kind  and  eondi- 
perim'ts  tion  of  food 


Dry    Organic 
matter    matter 


Digestion  coefficients 

Nitrogen- 
Pro-  free  ex- 

Ash       tein    Fiber     tract 

%  %  %  % 


Fat 


GREEN   FODDERS 
Meadow  Grasses 

3  .  Hungarian 67.2  68.6  52.2  64.3  71.2  67.9  65.7 

4  .  Barnyard  millet    .    .  66.6  67.  59.5  61.5  66.5  68.3  64.3 

1  .  Timothy 63.5  65.6  32.2  48.1  55.6  65.7  53.1 

1  .  Timothyrowen  .    .    .  64.8  66.4  45.2  71.7  63.8  67.8  £2.9 

1  .  Pasture  grass     .    .    .  68.7  70.  49.7  65.5  74.3  72.5  54.7 

1     Mixed- grass  rowen  .  65.6  67.4  46.2  67.4  62.6  71.6  55.2 


428 


Appendix 


No.  ex-        Kind  and  condi-  Dry  Organic 

perim'ts  tiou  of  food  matter    matter 

%         % 
Cereal  Plants 

2  Barley 65.9  67.5 

8  .  Dent  com,  immature   68.8  70.7 
6     Dent  corn,  mature    .    66.6  68.5 

14  .  Denteorn, all  samples  67.8  69.8 

6  .  Sweet  corn      ....    71.1  72.2 

3  .  Oats 59.5  60.9 

1  .  Rye 73.4  75.3 

2  .  Sorghum      67.3  69. 

Clovers  and  Legumes 

6  .  Alfalfa  (G) 64. 

1  .  Crimson  clover  .    .    .    67.9  69.1 

1  .  Red  clover 66.1  68.1 

1  .  Red    clover,    before 

bloom  (G) 74. 

2  .  Red  clover, beginning 

bloom  (G) 71. 

2     Red  clover,  bloom  to 

end  (G) 61. 

1  .  Red  clover  rowen  .    .    59.3  60.8 

1  .  Canada  peas  ....    68.4  71.3 

2  .  Cow  pea 68.3  74.1 

4  .  Soy  bean 59.8  64.5 

1  .  Common  vetch  .    .    .    61.8  65.7 

3  .  Hairy  vetch    ....    70.3  73.1 

Mixed 

1  .  Barley  and  peas    .    .    53.4  60.2 

4  .  Oats  and  peas    .    .    .    65.4  67.2 
1  .  Vetch  and  oats  ...    67.  68.4 

SILAGE 
Maize 

9  .  Denteorn    ....        65.1  67.1 
6     Flint  corn 73.1  76.1 

13  .  Denteorn,  immature    65.6  67.4 


^igesLi 

Ash 

% 

Pro- 
tein 

% 

Nitrogen 
free  ex- 
Fiber     tract 

%           % 

Fat 

% 

54.4 

71.8 

60.8 

71.2 

59.9 

45.4 

65.2 

66.6 

73. 

72. 

19.4 

52.3 

51.6 

74.7 

77. 

35.6 

59.7 

60.2 

73.7 

74.1 

55.3 

64. 

62.9 

76.6 

75.6 

53.4 

71.8 

52.8 

62.6 

69.2 

55.8 

79.4 

79.2 

70.1 

74.5 

42.4 

46.8 

59. 

74.6 

74.2 

81. 

41. 

72. 

45. 

56.1 

77.1 

56.1 

74.5 

60.5 

55. 

67. 

52.6 

77.6 

64.5 

•    • 

74. 

60. 

83. 

65. 

•    • 

74. 

57. 

79. 

71. 

64. 

44. 

71. 

53. 

43.4 

61.9 

52.5 

65.3 

60.8 

42.3 

82. 

62.4 

71. 

52.4 

22.8 

75.6 

59.6 

80.6 

59.4 

18.9 

75.1 

47. 

73.2 

54.1 

17.3 

71.4 

44.2 

76.1 

58.6 

45.1 

82.8 

61.1 

76.3 

71.6 

46.2 

77.2 

43.5 

6. .4 

59.7 

45.4 

76.1 

59.7 

67.7 

67.7 

52.7 

74.8 

68.3 

67.9 

47.2 

32.2  49.3 
32.9     62.8 

34.3  51.3 


66.7     68.6     80. 
75.1     76.9     81.8 
70.6    67.4     80.2 


DigestiMlity  of  Feeding  SUiffs  429 


, 



-Digest 

on  coefficients- 

Nitrogen 

No 

ex-        Kind  and  eondi- 

Dry 

Organic 

Pro- 

free ex- 

perim'ts           tiou  of  food 

matter 

matter    Ash 

tein 

Fiber 

tract 

Fat 

% 

% 

% 

% 

% 

% 

7o 

-T/otiC— continued 

10 

Dent  aiid  flint  corn, 

mature 

70.8 

73.6 

30.3 

56. 

70. 

76.1 

82.4 

1 

Sweet  corn 

Miscellaneous 

68.1 

70.1 

31.9 

54. 

71.1 

71.8 

83.5 

Cow  pea  .... 

59.6 

63.4 

30.3 

57.5 

52. 

72.5 

62.6 

Soy  bean  (steers) 

49.8 

53.8 

28. 

55.3 

42.9 

61.2 

48.9 

Soy  bean  (^oats)      . 

59. 

59.3 

56.7 

75.7 

54.8 

52. 

71.9 

Corn  and  soy  bean   . 

69. 

71. 

65. 

64.8 

74.9 

82.1 

Millet  and  soy  bean 

58.8 

59.9 

58.4 

69.4 

59.2 

72.2 

Corn,    horse    beans, 
and     sunflower 

beads    

65.6 

67.8 

41.1 

62.7 

60.1 

72.4 

76.7 

1 

Corn,    horse    beans, 
and    sunflower 

plants  

65.5 

69.3 

25.6 

58. 

65.3 

73.7 

74.1 

DRIED   FODDERS 

Meadoiv  Grasses 

1 

Black  grass   {Juncus 

htilhosus)      .    .    .    . 

59.5 

63. 

60.5 

57. 

41.5 

1 

Black  grass  {Juncus 

geranU) 

53.4 

52.1 

69. 

54.3 

57.4 

49. 

45.7 

2 

Blue  joint      .... 

54.3 

55.8 

29.4 

63.4 

54.5 

55.9 

44.7 

1 

Branch  grass  {Spar- 

tina  stricta glabra) 

56. 

62.5 

52. 

54. 

32. 

1 

Branch   grass  {Dis- 

tichbjs  spicata)  .    . 

49.7 

48.9 

58.1 

51.7 

56.4 

45.7 

36.6 

1 

Chess  or  cheat      .    . 

45. 

47.3 

23. 

42. 

46. 

49. 

32. 

2 

Crab  grass      .... 

53.6 

55. 

37.6 

59.1 

54.5 

46.8 

1 

Fox  grass  {Spartina 

patens) 

54.8 

54.5 

58.2 

59.3 

57.4 

53.1 

36.4 

1 

Fox  grass  {Spartina 

juncea,  etc.)  .    . 

53. 

57. 

51. 

52. 

24. 

1  - 

Flat  sage 

56.1 

57.3 

62. 

51.8 

60.4 

55.1 

36.1 

1  . 

Hungarian  grass  .    . 

65. 

66.3 

47.4 

60. 

67.6 

67.1 

63.9 

2 

Johnson  grass  .    .    . 

56.5 

58.3 

30.5 

41.4 

65.7 

56.9 

38.4 

430  Appendix 


, 

-Digestion  coefficients- 

Nitrogen 

No 

ex-        Kind  and  eondi- 

Dry 

Organic 

Pro- 

free ex- 

perim'ts           tion  of  food 

mutter 

matter    Ash 

tein 

Fiber 

tract 

Fat 

% 

% 

% 

% 

% 

% 

% 

Meadoiv  Grasses— contmiied 

1 

.  Barnyard  millet    .    . 

57.4 

56.8 

63.1 

63.7 

61.6 

51,6 

46.3 

1 

.  Cat-tail  millet  .    .    . 

62.3 

61.6 

68.4 

62.6 

66.5 

59.1 

46.1 

2 

.  Orchard  grass   .    .    . 

56.6 

57.8 

59.5 

60.4 

55.4 

53.8 

2 

.  Redtop 

59.7 

61.2 

29. 

61.3 

61.3 

61.9 

50.5 

1 

Redtop  and  sedge    . 

46. 

48.5 

10.1 

37.2 

55.7 

45.6 

49. 

17 

Timothy      .    .    . 

56.6 

57.9 

32.8 

46.9 

52.5 

62.3 

52.2 

3 

Timothy,    before    or 

in  bloom     .... 

60.7 

61.5 

44.2 

56.8 

58.8 

64.3 

58.4 

4 

Timothy,  past  bloom 

53.4 

54.5 

30.3 

45.1 

47.1 

60.4 

51.9 

1 

Timothy  rowen     .    . 

62.2 

64.4 

56.4 

68. 

66.5 

63.4 

49.5 

2 

Wild-oat  grass     .    . 

64. 

65.2 

34.7 

58.3 

67.9 

65.5 

50.5 

2 

Witch  grass  .... 

6L.2 

62.3 

40.9 

58.6 

62.8 

65.6 

57.2 

1 

Black  grass  and  red- 

top  (cove  mixture) 

54.6 

54.3 

57.5 

47.9 

59.7 

53.2 

40.3 

5 

Mixed  grasses   .    .    . 
Meadow  hay- 

57.1 

58.8 

58.5 

59.7 

58.7 

48.5 

Best  (G)     .... 

67. 

65. 

63. 

68. 

57. 

Medium  (G)  .    .    . 

61. 

57. 

60. 

64. 

.53. 

Poor  (G)     .... 

56. 

50. 

56. 

59. 

49. 

2 

Pasture  grass    .    .    . 

72.6 

73.2 

51.8 

73.4 

76.1 

74.2 

67.3 

1 

.  Swale  hay 

39. 

34. 

33. 

46. 

44. 

1 

High  grown  salt  hay 

53. 

63. 

50. 

53. 

47. 

1 

Salt- hay  mixture  .    . 

56.4 

54.9 

69.8 

42.6 

60.7 

54.7 

29.7 

2 

Rowen  hay     .... 
Cereal  Plants 

64.4 

65.8 

46.6 

69.1 

66.6 

66.2 

47.4 

1 

Barley  hay     .    .    . 

61.2 

62.3 

44.8 

65.2 

61. 7 

63.3 

40.5 

17 

Dent  corn  fodder     . 

64.3 

66.1 

30.7 

50.4 

62.2 

68. 

73.6 

7 

Flint  corn  fodder     . 

68.6 

71.7 

42.6 

60. 

74.9 

70.3 

71.4 

13 

Dent  and  flint  corn 

fodders  (immature)  63.9     65.7     37.2     51.7     66.       66. 
10  .  Dent  and  flint  corn 

fodders  (mature)  .  68.2 
3  .  Sweet  corn  fodder  .  67.2 
5  .  Corn  stover    ....    57.2 


70.7 

30.6 

56.1 

65.8 

72.2 

73.9 

69.8 

35.6 

64.1 

73.8 

68.2 

73.6 

59.1 

32.6 

,35.9 

64.2 

57.9 

70.4 

Digestibility  of  Feeding   Stuffs 


431 


Digesti 

on  coemcients 

Nitrogen 

No 

ex-        Kind  and  condi- 

Dry 

Organic 

Pro- 

free ex- 

pen 

m'ts           tion  of  food 

matter 

matter    Ash 

tein 

Fiber 

tract 

i'at 

% 

% 

% 

% 

% 

% 

% 

Cereal  Pia/i^s— continued 

3 

New  corn  product    . 

58.1 

59.2 

38.7 

46.7 

57. 

60.5 

78.2 

2 

Topped  corn  fodder 

57.4 

62.3 

3.8 

38.7 

71. 

57.9 

67.4 

1 

Corn    blades    and 

husks       

63.8 

67.1 

22.6 

47.7 

72.9 

66.4 

58.1 

2 

Corn  leaves  (pulled 

fodder) 

59.8 

63.6 

26.8 

48.4 

67.5 

63. 

59.9 

1 

Corn  husks     .... 

72. 

74.2 

16. 

29.5 

79.5 

75. 

32.5 

1 

Corn  butts 

66.5 

69.4 

11.5 

21. 

73.5 

69. 

79.5 

1 

Oat  hay 

49.3 

50.1 

34.6 

54.2 

43.5 

52. 

61.9 

1 

Oat  straw 

50.3 

52. 

57.6 

53.2 

38.3 

Bean  straw        .    .    . 

55. 

49. 

43. 

67. 

57. 

Wheat  straw  (G)  .    . 

46. 

23. 

55. 

39. 

36. 

Rye  straw  ( G)  .    .    . 

.    . 

48. 

.    . 

25. 

63. 

39. 

29. 

Barley  straw  (G) 

.    . 

53. 

25. 

55. 

54. 

42. 

Kice  straw  (G)  . 

47. 

45. 

57. 

32. 

47. 

1 

Sorghum     fodder 

(pulled) 

63.1 

64.8 

29.5 

60.8 

70.4 

64.5 

46.7 

1 

Sorghum  bagasse     . 
Clovers 

60.6 

62.2 

13.4 

13.7 

63.8 

64.8 

46.4 

2 

.  Alsike  clover     .    .    . 

62.3 

63.2 

52.2 

66.1 

53.5 

70.7 

50.2 

4 

Crimson  clover     .    . 

58.1 

59.1 

51.9 

68.7 

46.7 

64.6 

43.4 

6 

.  Red  clover     .... 

57.4 

59.7 

29.1 

58. 

54.2 

64.4 

55.2 

2 

.  Red  clover  rowen     . 

58. 

59.1 

45.8 

64.8 

47.4 

62.8 

59.8 

1 

White  clover         .    . 

66. 

66.6 

58.5 

73.2 

60.6 

69.5 

50.6 

Legumes  other  than  Clovers 

3 

.  Alfalfa 

58.9 

60.7 

39.5 

72. 

46. 

69.2 

51. 

1 

.  Cow  pea  vine     .    .    . 

59.2 

60. 

49.5 

64.8 

42. 

70.6 

51.8 

1 

.  Peanut  vine  .... 

59.9 

63.1 

20.4 

63.3 

51.9 

69.5 

65.9 

1 

.  Soy  bean 

62.4 

63.9 

71.1 

60.8 

68.8 

29.2 

1 

.  Hairy  vetch    .... 

69.4 

71.8 

42  2 

82.3 

61.1 

72.9 

70.3 

Bean  straw  (G)    .    . 

55. 

49. 

43. 

67. 

57. 

Pea  straw,  good  (G) 

59. 

60. 

52. 

64. 

46. 

432 


Appendix 


No.  ex-        Kind  and  con<li- 
perim'ts            tion  of  food 

Dry 

matter 

Ort^anic 
matter    A.sh 

ou  coei 

Pro- 
tein 

Nitrogen 
free  ex- 
Fiber      tract 

Fat 

Miscellaneous  and  Mixed 

% 

%            % 

% 

% 

% 

% 

1 

.  Buttercup  hay  .    .    . 

56.1 

56.6    48.1 

56.3 

41.1 

66.9 

69.7 

1 

.  Whiteweed  hay     .    . 

57.8 

58.3     52. 

58.4 

45.5 

66  7 

62. 

o 

Clover  and  timothy  . 

54.6 

53.2      .    . 

42.3 

49.6 

57.5 

54. 

1 

Vetch  and  oats  .    .    . 
Grains  and  Seeds 

58.1 

58.7      .    . 

59.7 

66. 

54.2 

18.6 

Barlev  (G)      .... 

86.        .    . 

70. 

92. 

89. 

Oats  (G) 

71.        .    . 

78. 

26. 

77. 

83. 

5 

Corn  meal 

89.4 

89.6      .    . 

67.9 

94.6 

92.1 

2 

Corn-and-cobmeal  . 

78.7 

79.8 

55.6 

45.7 

87.6 

84.1 

] 

Rye  meal 

87.3 

88.7      .    . 

84.4 

91.9 

64.2 

1 

Pea  meal 

86.8 

87.9     43.7 

83.2 

25.7 

93.6 

54.5 

Field  beans    .... 

89.        .    . 

88. 

72. 

92. 

81. 

1 

Soy-bean  meal  .    .    . 

81.9 

84.        .    . 

91  1 

71.2 

76.3 

85.7 

1 

Cottonseed,    raw  .    . 

66.1 

65.8     43.3 

67.8 

75.5 

49.6 

87.1 

1 

Cottonseed,   roasted 

55.9 

56.8 

46.9 

65.9 

51.4 

71.7 

Linseed  

77.        .    . 

91. 

60. 

55. 

86. 

Acorns 

88.        .    . 

83. 

62. 

91. 

87. 

BY-PRODUCTS 

Cereals 

1 

Atlas  meal 

79.6 

83.4      .    . 

72.8 

105.7 

84.5 

91.2 

1 

Cereal  ine  feed  .    .    . 

90.4 

92.7      .    . 

76.6 

82.2 

95.3 

80.6 

2 

Corncobs     

51.4 

19.3 

57.5 

48.3 

.    . 

1 

Dried  brewers'  grains 

61.6 

65.4      .    . 

79.3 

52.6 

57.8 

91.1 

5 

Gluten  feed    .... 

86.3 

87.3      .    . 

85.6 

78. 

89.2 

84.4 

4 

Gluten  meal  .... 

89.7 

90.4      .    . 

88.2 

89.8 

94.4 

1 

H.  0.  dairy  feed   .    . 

65.3 

68.        .    . 

77.8 

40.8 

69.9 

85.5 

1 

H.  0.  horse  feed  .    . 

70.1 

72.6      .    . 

74.4 

35.2 

78.7 

84. 

1 

Maize  feed     .... 

87.1 

87.1 

85.5 

82.5 

87.9 

91.5 

1 

Malt  sprouts  .... 

67.1 

67.2      .    . 

80.2 

32.9 

68.1 

104.6 

1 

Quaker  oat  feed    .    . 

62. 

65.3      .    . 

81.1 

42.6 

67.4 

89. 

1 

.  Victor   corn -and -out 
feed 

74.7 

77.4      .    . 

70.8 

48.3 

83. 

86.8 

Digesfihnitj/  of  Feeding  Stuff's 

■ Digestion  coefficients 

Nitrogen- 
No.  ex-        Kind  anil  condi-  Dry    Organic  Pro-  free  ex- 


433 


aer 

m'ts            tion  of  food 

matter 

matter    Ash 

tein 

Fiber 

tract 

Fat 

% 

% 

% 

% 

% 

% 

% 

Ccreai— continued 

7 

.  Wheat  bran    .... 

G2.3 

65.7 

.    , 

77.8 

28.6 

69.4 

68. 

1 

.Wheat   bran    and 

shorts 

60.2 

60.7 

7.5 

75.8 

18.3 

64.3 

45. 

3 

.  Wheat  middlings  .    . 
Oil-bearing  Seeds 

75. 

78.5 

79.8 

33.1 

81.3 

86.3 

3 

.  Cottonseed  hulls  .    . 

39.8 

40.5 

23.2 

40. 

41.1 

85.7 

5 

.  Cottonseed  meal  .    . 

73.7 

76.1 

23.7 

88.4 

55.5 

60.6 

93.? 

1 

.  Linseed  meal,  old 

process    

78.7 

81.2 

88.8 

57. 

77.6 

88.6 

2 

.  Linseed    meal,    new 

process    .    . 

79.2 

81.8 

85.2 

80.4 

86.1 

96.6 

llisccllaneous 

1 

Peanut  feed   .... 

32.1 

32.8 

70.6 

11.7 

49.1 

89.7 

1 

Rice  meal 

ROOTS 

73.8 

81.6 

61.9 

•    • 

92.3 

91.1 

1 

Mangolds 

78.5 

84.8 

16.4 

74.7 

42.8 

91.3 

.    . 

1 

Potatoes,  raw     .    .    . 

75.7 

77. 

44.7 

90.4 

13. 

1 

Potatoes,  boiled    .    . 

80.1 

81.2 

.    . 

43.4 

.    . 

92.1 

.    . 

1 

Rutabagas  ... 

87.2 

91.1 

31.2 

80.3 

74.2 

94.7 

84.2 

1 

Sugar  beets    .... 

94.5 

98.7 

31.9 

91.3 

100.7 

99.9 

49.9 

1 

Turnips 

ANIMAL    PRODUCTS 

92.8 

96.1 

58.6 

89.7 

103. 

.96.5 

87.5 

Cow's  milk  (G)  .    .    . 

.    . 

98. 

.    , 

94. 

.    . 

98. 

100. 

Meat  meal  (G)  .    .    . 

93. 

.    . 

96. 

99. 

Dried  blood  (G)    .    . 

.    . 

63. 

.    . 

62. 

100. 

100. 

Dried  fish,  ground(G) 

•    • 

•    • 

90. 

•    • 

•    • 

76. 

Digestion  hij  Horses 

Dried  Fodders 

2 

Timothy  hay  in  full 

bloom, well  cured  . 

43.5 

44.1 

34. 

21.2 

42.6 

47.3 

47.3 

2 

New  corn  product    . 

49.9 

51.7 

21.7 

67.5 

54.6 

46.9 

59.8 

BB 


434 


Appendix 


' 

j^ise&Li 

uii  cueu 

Nitrogen 

No 

ex-        Kind  and  condi- 

Dry 

Organic 

Pro- 

free ex- 

perim'ts          tiou  of  food 

matter 

matter    Ash 

tein 

Fiber 

tract 

Fat 

% 

% 

% 

% 

% 

% 

% 

Dried  Fodders— <:ontin\ied 

Meadow  hay— 

Best  (G)      .... 

58. 

63. 

48. 

65. 

22. 

Medium  (G)  .    .    . 

50. 

57. 

39. 

58. 

18. 

Poor  (G)     .... 

46. 

55. 

38. 

52. 

24. 

Red  clover  hay  (G)    . 

51. 

56. 

37. 

63. 

29. 

Alfalfa  hay  (G)    .    . 

58. 

73. 

40. 

70. 

14. 

Wheat  straw  (G)  .    . 

21. 

.     . 

28. 

18. 

28. 

66. 

Hoots 

Potatoes  (G)  .    .    .    . 

93. 

88. 

99. 

Carrots  (G)     .... 

.     . 

87. 

.      . 

99. 

.    . 

94. 

.    . 

Grains 

Oats  (G)     ..... 

69. 

.      . 

79. 

29. 

75. 

71. 

Barley  (G)     .... 

87. 

80. 

87. 

42. 

Corn  (G)     .    . 

.     .' 

89. 

76. 

40. 

92. 

61. 

Field  beans  (G)    .    . 

87. 

.      . 

86. 

65. 

94. 

13. 

Peas(G)  

80. 

83. 

8. 

89. 

7. 

>> 

Dent  corn,  unground 

74.4 

75.3 

26.3 

57.8 

(n 

88.2 

47.7 

2 

.  Corn    meal,     same 

material,  ground  . 

88.4 

75.6 

(?) 

95.7 

73.1 

o 

.  White    oats,    first 

quality,  unground 

72.4 

74.1 

33.1 

86.1 

31.1 

79.4 

82.4 

(> 

.  Oats,  same  material, 

ground 

75.7 

77.7 

29.2 

82.4 

14.4 

86.1 

79.9 

Digestion  hij 

Swine 

Grains  and  Seeds 

1 

.  Barley,  whole  kernel 

80.1 

80.3 

5.4 

81.4 

48.7 

86.6 

57. 

1 

.  Flint  corn,  unground 

82.5 

83.4 

68.7 

38.3 

88.8 

45.6 

1 

.  Flint  corn,  unground 

89.7 

91.3 

.    . 

89.9 

48.7 

93.9 

77.6 

1 

.  Corn    meal,     same 
material,    finely 

ground 

89.5 

91.2 

.    . 

86.1 

29.4 

94.2 

81.7 

1 

.  Corn -and -cob  meal, 

whole  ear  ground. 

75. G 

76.7 

.    . 

75.7 

28.5 

83.6 

82. 

Feeding   Standards 


435 


No.  ex-        Kind  and  condi- 
perim'ts            tion  of  food 

Dry 

matter 

Organic 
matter    Ash 

ou  coei- 

Pro- 
teiu 

ueiems 

Nitroyeu 
free  ex- 
Fiber      tract 

Fat 

Grains  and  Seeds— con- 
tiuued 

% 

% 

% 

% 

% 

% 

% 

? 

.  Wheat,  unground 

.    72. 

44. 

70. 

30. 

74. 

60. 

? 

.  Wheat,  cracked    . 

82. 

50. 

80. 

60. 

83. 

70. 

1 

Peas,  ground    .    . 
By-products 

89.8 

91.5 

40.3 

88.6 

77.9 

95.1 

50. 

1 

.  Wheat  bran    .    .    . 

.    65.8 

75.1 

33. 

65.5 

71. g 

Rye  bran  (G)     .    . 

67. 

66. 

9. 

74. 

58. 

o 

Wheat  shorts     .    . 

7(j.5 

5.4 

73.5 

36.5 

86.8 

2 

Linseed  meal    .    . 
Roots 

77.5 

10. 

86. 

12. 

85. 

80. 

2 

Potatoes,  raw    .    . 

97. 

44.6 

84.5 

98.1 

.    . 

2 

Potatoes,  cooked  . 

Animal  Products 
Meat  meal  (G)  .    . 
Dried  blood  (G)     . 

95. 

92. 
72. 

40. 

82. 

97. 

72. 

97.6 
92. 

86. 

Sour  milk  (G)  .    . 

.    . 

95. 

96. 

,    . 

98. 

95. 

3.    FEEDING   STANDARDS 


The  feeding  staudards  for  the  various  classes  of 
farm  animals  are  taken  from  Mentzel  &  Leugerke's 
Landw.  Kalender  for  1899.  They  are  intended  to  apply 
to  animals  of  average  size  fed  under  normal  conditions. 
They  are  not  to  be  regarded  as  feeding  recipes,  but  are 
to  be  varied  according  to  circumstances.  Small  animals 
should  receive  proportionately  more  food  than  large 
ones  ;  milch  cows  in  proportion  to  the  quantity  and 
richness  of  the  milk ;  growing  and  fattening  animals 
according   to   the    rapidity   of   increase   desired ;    work 


436  Appendix 

animals  according  to  the  severity  of  labor,  and  indi- 
vidual animals  according  to  their  peculiar  needs. 

The  quantity  of  "dry  substance"  will  vary  according 
to  the  digestibility  of  the  ration,  with  no  harm.  It  is 
important  to  maintain  the  necessary  quantity  of  diges- 
tible dry  substance.  This  should  be  somewhat  more  if 
the  ration  has  a  larger  proportion  of  coarse  materials 
than  when  it  is  mostly  grain.  The  nutritive  ratio  may 
wiselj"  vary  according  to  the  availability  and  price  of 
feeding  stuffs.  The  method  of  calculating  a  standard 
ration  is  explained  in  Chapter  XIX. 

Per  1,000  Lbs.  Live  Weight,  Daily 
Dry    '— Digestible  organif  substances— -     Nutri- 
sub-      Pro-      Carbo-  tive 

Kiud  of  auimal  stance    tein    liydrates    Fat  Total      ratio  1: 

lbs.       lbs.         lbs.  lbs  lbs. 

1  .  Oxeii  — 

At  rest 18         .7        8.  .1  8.8  11.8 

Lightwork 22  1.4  10.  .3  11.7  7.7 

Moderate  work  ...  25  2.  11.5  .5  14.  6.5 

Severe  work    ....  28  2.8  13.  .8  16. G  •   5.3 

2  .  Fattening  bovines — 

First  period    ....  30  2.5  15.  .5  18.  6.5 

Second  period    ...  30  3.  14.5  .7  18.2  5.4 

Third  period  ....  26  2.7  15.  .7  18.4  6.2 

3  .  Milch  cows — 

Daily  milk  yield   11 

lbs 25      1.0      10.  .3        11.9  6.7 

Daily  milk  yield  16X 

lbs 27      2.         11.  .4        13.4  6. 

Daily  milk  yield   22 

lbs •   .    29      2.5      13.  .5        16.  5.7  ' 

Daily  milk  yield  27X 

lbs ".32      3.3      13.  .8        17.1  4.5 

4  .  Sheep— 

Coarse  wool    ....    20      1.2       10.5  .2        11.9  9.1 

Fine  wool 23      1.5      12.  .3       13.8         8.5 


Feeding  Standards 


437 


Per  1,000  Lbs.  Lite  Weight,  Daily 


Dry    '—Digestible  organic  substances— - 
snb-      Pro-      Carbo- 


Xntri- 
tive 


Kind  of  anima 

stance 

tein 

hydrates 

Fat 

Total 

ratio  1 

lbs. 

lbs. 

lbs. 

lbs. 

lbs. 

5  .  Ewes,  suckling 

lambs  . 

25 

2.9 

15. 

.5 

18  4 

5.6 

6  .  Fattening  sheep 

— 

First  period 

30 

3. 

15. 

.5 

18.5 

5.4 

Second  perioc 

28 

3.5 

14.5 

.6 

18.6 

4.5 

7  .  Horses — 

Light  work  . 

20 

1.5 

9.5 

.4 

11.4 

7. 

Moderate  wor 

k    .    . 

24 

o 

11. 

.6 

13.6 

6.2 

Severe  work 

26 

2.5 

13.3 

.8 

16.6 

6. 

8  .  Brood  sows 

22 

2.5 

15.5 

.4 

18.4 

6.6 

9  .  Fattening  swine — 

First  period 

36 

4.5 

25. 

.7 

30.2 

5.9 

Second  period    .    .    . 

32 

4. 

24. 

.5 

28.5 

6.3 

Third  period 

25 

2.7 

18. 

.4 

21.1 

7. 

0           GROWING  CATTLE 

Daini  Breed. 

Live  weight 
Age  in                        per  head 
months                            lbs. 

2-3 

150  . 

23 

4. 

13. 

2, 

21. 

4.5 

3-6      

300  . 

24 

3. 

12.8 

1. 

16.8 

5.1 

G-12 

500  . 

27 

2. 

12.5 

.5 

15. 

6.8 

12-18    

700  . 

26 

l.S 

12.5 

.4 

14.7 

7.5 

18-24    

900  . 

26 

1.5 

12. 

.3 

13.8 

8.5 

Beef  Breeds 
2-3 

165  . 

23 

4.2 

13. 

2. 

19.2 

4.2 

3-6      

330  . 

24 

3.5 

12.8 

1.5 

17.8 

4.7 

6-12 

550  . 

25 

2.5 

13.2 

.7 

16.4 

6. 

12-18    

750  . 

24 

2 

12.5 

.5 

15. 

6.8 

18-24    .... 

935  . 

24 

1.8 

12. 

.4 

14.2 

7.2 

GROWING    SHEEP 

Wool  Breeds 
4   6 

60  . 

25 

3.4 

15.4 

.7 

19.5 

5. 

6-8 

^5  . 

25 

2.8 

13.8 

.6 

17.2 

5.4 

8-11 

85  . 

.    23 

2.1 

11.5 

.5 

14.1 

6. 

438 


Appendix 


Kind  of  auimal 

Wool  Breeds— continued. 

Live  weight 


Dry 

sub- 
stance 
lbs. 


Per  1,000  Lbs.  Live  Weight,  Daily 


Age  in 
months 


per  head 
lbs. 


±o    ^v 

Mutton  Breeds 

J.UU    .       . 

4-6      

65      . 

6-8 

85  .    . 

8-11 

100  .    . 

11-15    

120  .    . 

15-20    

150  .    . 

22 
22 


Digestible  organic  substances— ^ 
Pro-      (\-irbo- 

tein    hydrates    Fat         Total 
lbs,         lbs.         lbs.  lbs. 


1.8 
1.5 


11.2 
10.8 


26  4.4  15.5 

26  3.5  15. 

24  3.  14.3 

23  2.2  12.6 

22  2.  12. 


13.4 
12.6 

20.8 
19.2 
1.78 
15.3 
12.4 


Nutri- 
tive 
ratio  1; 


4. 

4.8 

5.2 

6.3 

6.5 


GROWING   SWINE 


Breeding  -S 

lock 

2 

3      .    .    . 

.     45 

3-5      ... 

.   100 

5- 

-6     .    .    . 

.   120 

6 

8      .    .    . 

.   175 

8- 

-12    .    .    . 

.   260 

roi 

ving  Fattenin 

g  Anivu 

2- 

-3      .    .    . 

.      45 

3 

5      .    .    . 

.   110 

5- 

-6      .    .    . 

.   150 

6 

8      .    .    . 

.  200 

8- 

-12    .    .    . 

.  275 

44 


7.6      28. 


35  5.  23.1 

32  3.7  21.3 

28  2.8  18.7 

25  2.1  15.3 


44  7.6  28. 

35  5.  23.1 

33  4.3  22.3 

30  3.6  20.5 

26  3.  18.3 


1. 


35.7 


.8 

28.9 

5. 

.4 

25.4 

6. 

.3 

21.8 

7. 

.2 

17.6 

7.5 

35.7 

4. 

.8 

28.9 

5. 

.6 

27.2 

5.5 

.4 

24.5 

6. 

.3 

21.6 

6.4 

Fertilizing   Constituents  439 


4.  FERTILIZING    CONSTITUENTS    OF   AMERICAN 
FEEDING    STUFFS 

This  table  is  the  one  prepared  by  the  offices  of  Ex- 
periment Stations,  U.  S.  Department  of  Agriculture, 
and  published  in  the  Handbook  of  Experiment  Sta- 
tion Work,  Bulletin  No.  15. 

Plios-      Potas- 

phorie       slum 

Moisture        Ash        Nitrogen     acid         oxide 

%  %  %  %  % 

Green  Fodders 

Corn  fodder 78.61         4.84  .41         .15         .33 

Sorghum  fodder 82.19  .    .  .23         .09         .23 

Rye  fodder      62.11  .    .  .33         .15         .73 

Oat  fodder 83.36         1.31  .49         .13         .38 

Common  millet 62.58  .    .  .61         .19         .41 

Japanese  millet 71.05  .    .  .53         .2  .34 

Hungarian    grass    (German 

millet) 74.31  .    .  .39         .16         .55 

Orchard    grass    {Dactyli s 

glomerala)'^ 73.14         2.09  .43         .16         .76 

Timothy  grass  (Phlcum  pra- 

tense'f 66.9  2.15  .48         .26         .76 

Perennial  rve  grass  [Lolinm 

perenne)* 75.2  2.6  .47         .28       1.1 

Italian    rye    grass    {Lolinm 

italicum)'^ 74.85         2.84  .54         .29       1.14 

Mixed  pasture  grasses    .    .      63  12         3.27  .91         .23         .75 

Red  clover  {TrifoUum  pra- 

tense) 80.  .    .  .53         .13         .46 

White  clover  {TrifoUum  re- 
pens)  81.  .    .  .56         .2  .24 

Alsike  clover  {TrifoUum  hy- 

bridum) '.      81.8  1.47    ,     .44         .11         .2 

Scarlet  clover  {TrifoUum  in- 

carnntum) 82.5  .    .  .43         .13         .49 

Alfalfa  {Medicago  saiiva)    .      75.3  2.25  .72         .13         .56 

*Dietrich  and  Konig:  Zusamensetzung  und  Verdaulielikeit  der  Futtermittei. 


440 


Appendix 


Moisture  Ash 

%  % 
Green  J^'odders— continued 

Cow  pea 78.81  1.47 

Serradella     (Ornithojns    sa- 

tivus) 82.59  1.82 

Soja  bean  (Glycine  soja)    .  73.2 

Horse  bean  [Vicia  faba)  .    .  74.71  .    . 

Yfh.\ie\vi^ue  [Lupinus  alhus)  85.35  .    . 

Yellow  lupine  {Lupinus  lu- 

teus)^ 83.15  .96 

Flat  pen  (Lathyrussylvestris)*  7I.G  1.93 

Common  vetch  ( Vicia  sativa)*  84.5  1 .94 

Prickly  comfrey  {Symphy- 
tum asperrimum)   ....  84.36  2  45 

Corn  silage 77.95  .    . 

Corn  and  soja  bean  silage  .  71.03  .    . 

Apple  pomace  silage^  ...  75.  1.05 

Hay  and  Dry  Coarse  Fodders 

Corn  fodder  (with  ears)      .        7.85  4.91 

Corn  stover  (without  ears)  .        9.12  3.74 

Teos\nte{Euc1il(enalnxuria)i.s)     6.06.  6.53 

Common  millet 9.75  .    . 

Japanese  millet 10.45  5.8 

Hungarian  grass 7.69  6.18 

Hay  of  mixed  grasses  .    .    .  11.99  6.34 

Rowen  of  mixed  grasses.    .  18.52  9.57 

Hedtoi)  {Agwstis  vulgaris)  .        7.71  4.59 

Timothy 7.52  4.93 

Orchani  grass 8.84  6.42 

Kentucky    blue -grass    [Poa 

pratcnsis) 10.35  4.16 

Meadow  fescue  ( Fcsfuca,  pra- 
tcnsis)           8.89  8.08 

Tall  meadow  oat  grass  (Ar- 

rhenatcerum  avc)i(trrum)    .  15.35  4.92 

*  Dietrich  and  Konig. 


Nitrogen 


.27 


Phos- 
phorie 
iieid 


Potas- 
sium 
oxide 


.31 


.41 

.14 

.42 

.29 

.15 

.53 

.68 

.33 

1.37 

.44 

.35 

1.73 

.51 

.11 

.15 

1.13 

.18 

.58 

.59 

1.19 

.7 

.42 

.11 

.75 

.28 

.11 

.37 

.79 

.42 

.44 

.32 

.15 

.4 

1,76 

.54 

.89 

1.04 

.29 

1.4 

1.46 

.55 

3.7 

1.28 

.49 

1.69 

1.11 

.4 

1.22 

1.2 

.S5 

1.3 

1.41 

.27 

1.55 

l.Gl 

.43 

1.49 

1.15 

.36 

1.02 

1.26 

.53 

9 

1.31 

.41 

1.88 

1.19 

.4 

1.57 

.99 

.4 

2.1 

1.16 

.32 

1.72 

Fertilizing   Constiiuents 


441 


Moisture       Ash 

%  % 

nay  and  Dry  Coarse  Fodders— 
coutinued 

Meadow  foxtail  {Alopecurus 

pratensis) 15.35         5.24 

Perennial  rye  grass  .    ...  9.13         G.79 

Italian  rye  grass 8.7i 

Salt  marsh  hay      5.36 

Japanese  buckwheat    ...  5.72 

Red  clover 11.33         6.93 

Mammoth  red  clover  {Tri- 

folium  medium) 11.41         8.72 

White  clover 

Scarlet  clover* 18.3          7.7 

Alsike  clover 9.94       11.11 

Alfalfa      6.55         7.07 

Blue  melilot( Melilofus 

ccvnileus)      8.22       13.65 

Bokhara   clover    {Meliloius 

alba)      .    .        7.43         7.7 

Samioin  {Onohrijchis  safira)  12.17         7.55 
Sulla  {JTedysaruvi   coro- 

narinm) 9.39          .    . 

Lotus  villosus 11.52         8.23 

Soja  bean  (whole  plant)     .  6.3          6.47 

Soja  bean  (straw)      ....  13. 

Cow  pea  (whole  plant)    ,    .  10.95        8.4 

Serradella 7.39      10  6 

Scotch  tares 15.8           .    . 

Oxeye    daisy    {Chrysanthe- 
mum Jeucanthemum)  .    .    .  9.65         6.37 

Dry  carrot  tops 9.76       12.52 

Barley  straw 11.44        5.3 

Barley  chaff       ......  13.08          .    . 

Wheat  straw 12.56         3.81 

Wheat  chaff 8.05         7.18 

*  Dietrich  and  Konig. 


itrogen 

Phos- 
phoric 
acid 

Potas- 
sium 
oxide 

% 

% 

% 

1.54 

.44 

1.99 

1.23 

.56 

1.55 

1.19 

.56 

1.27 

1.18 

.25 

.72 

1.63 

.85 

3.32 

2.07 

.38 

2.2 

2.23 

.55 

1.22 

2.75 

.52 

1.81 

2.05 

.4 

1.31 

2.34 

.67 

2.23 

2.19 

.51 

1.68 

1.92 


.54 


1.98 

.56 

1.83 

2.63 

.76 

2.02 

2.46 

.45 

2.09 

2.1 

.59 

1.81 

2.32 

.67 

1.08 

1.75 

.4 

1.32 

1.95 

.52 

1.47 

2.7 

.78 

.65 

2.96 

.82 

3. 

.28 

.44 

1.25 

3.13 

.61 

4.88 

1.31 

.3 

2.09 

1.01 

.27 

.99 

.59 

.12 

.51 

.79 

.7 

.42 

442 


Hay  and  Dry  Coarse  Fodders- 
continued 

Rye  straw 

Oat  straw 

Buckwheat  hulls 


Appendix 


Moisture 

% 

7.61 
9.09 
11.9 


Hoots,  Bulbs,  Tubers,  etc. 

Potatoes 79.75 

Red  beets 87.73 

Yellow  fodder  beets     ...  90.6 

Sugar  beets 86.95 

Mangel -wurzels 87.29 

Turnips 89.49 

Rutabagas 89.13 

Carrots 89.79 


Grains  and  Other  Seeds 
Corn  kernels  .... 
Sorghum  seed    .... 

Barley* 

Oats      

Wheat  (spring)  .... 
Wheat  ( winter)  .... 

Rye 

Common  millet  .... 
Japanese  millet     .    .    . 

Rice 

Buckwheat , 

Soja  beans 

Mill  Products 
Corn  meal   .... 
Corn -and -cob  meal 
Ground  oats    .    .    . 
Ground  barley    .    . 
Rye  flour     ,    .    . 


10.88 

14. 

14.3 

18.17 

14.35 

14.75 

14.9 

12.68 

13.68 

12.6 

14.1 

18.33 

12.95 

8.96 

11.17 

13.43 

14.2 


Ash 


3.25 
4.76 


.99 
1.13 

.95 
1.04 
1.22 
1.01 
1.06 
9.22 

1.53 

2.48 
2.98 
1.57 


.82 


4.99 


1.41 


3.37 
2.06 


Phos-  Potas- 

phorie       shim 

Nitrogen      acid  oxide 

%  %  % 


.46  .28  .79 
.62  .2  1.24 
.49         .07         .52 


.21 
.24 
.19 
.22 
.19 
.18 
.19 
.15 

1.82 
1.48 
1.51 
2.06 
2.36 
2.36 
1.76 
2.04 
1.73 
1.08 
1.44 
5.3 

1.58 
1.41 
1.86 
1.55 
1.68 


.07 

.09 

.09 

.1 

.09 

.1 

.12 

.09 

.7 
.81 
.79 
.82 
.7 
.89 
.82 
.85 
.69 
.18 
.44 
1.87 

.63 

.57 
.77 
.66 
.85 


.29 
.44 
.46 
.48 
.38 
.39 
.49 
.51 

.4 
.42 
.48 
.62 
.39 
.61 
.54 
.36 
.38 
.09 
.21 
1.99 

.4 

.47 

.59 

.34 

.65 


Dietrich  and  Kiinig. 


Fertilizing   Consiituents 


443 


Moisture  Ash 

%  % 

Mill  Products — continued 

Wheat  aour 9.33  1.22 

Pea  meal 8.85  2.68 

By-products  and  Waste  Materials 

Corn  cobs 12.09  .82 

Hominy  feed 8.93  2.21 

Gluten  meal 8.59  .73 

Starch  feed  (glucose  refuse)        8.1  .    . 

Malt  sprouts ]0.38  12.48 

Brewers'  grains  (dry)  .    .    .        6.98  6.15 

Brewers'  grains  (wet)     .    .  75.01 

Rye  bran 12.5  4.6 

Rye  middlings*     ....  12.54  3.52 

Wheat  bran 11.74  6.25 

Wheat  middlings 9.18  2.3 

Rice  bran 10.2  12.94 

Rice  polish 10.3  9. 

Buckwheat  middlings*    .    .  14.7  1.4 

Cottonseed  meal 9.9  6.82 

Cottonseed  hulls 10.63  2.61 

Linseed  meal  (old  process)        8.88  6.08 

Linseed  meal  (new  process)        7.77  5.37 

Apple  pomace 80.5  .27 

*  Dietrich  and  Konig 


S^itrogeu 

Phos- 
phoric 
acid 

Potas- 
sium 
oxide 

% 

% 

% 

2.21 

.57 

.54 

3.08 

.82 

.99 

.5 

.06 

.6 

1.63 

.98 

.49 

5.03 

.33 

.05 

2.62 

.29 

.15 

3.55 

1.43 

1.63 

3.05 

1.26 

1.55 

.89 

.31 

.05 

2.32 

2.28 

1.4 

1.84 

1.26 

.81 

2.67 

2.89 

1.61 

2.63 

.95 

.63 

.71 

.29 

.24 

1.97 

2.67 

.71 

1.38 

.68 

.34 

6.64 

2.68 

1.79 

.75 

.18 

1.08 

5.43 

1.66 

1.37 

5.78 

1.83 

1.39 

23 

.02 

.13 

INDEX 


Absorption  of  food,  119. 

Acids,  83;  action  on  albnminoids,  65; 
action  on  carboliydrates,  86;  fatty, 
90;  influence  on  digestion,  139. 

Age,  influence  on  production,  411. 

Air,  carbon  in,  13;  liydrogeu  in,  1.3; 
nitrogen  in,  16;  oxygen  in,  14. 

Albuminoids,  57;  action  of  acids  and 
alkalies  on,  65;  action  of  heat  on,  64; 
action  of^  ferments  on,  63,  65;  com- 
parative energy  values  of,  173;  com- 
pounds among,  57;  energy  of,  162; 
modified,  62. 

Albumins,  58;  in  milk,  meat,  eggs,  58; 
in  plants.  59;  properties  of,  58;  where 
found,  58. 

Alfalfa,  as  soiling  crop,  266;  produc- 
tivity of,  261. 

Alkalies,  action  on  albuminoids,  65. 

Amides,  69;  value  of,  179. 

Animal,  globulins  in,  60;  water  in,  38. 

Animal  body,  distribution  of  ash  com- 
pounds in,  49. 

Animal  heat,  source  of,  9. 

Animal  life,  relation  of  oxj^gen  to,  14; 
relation  of  plant  to,  7;  relation  to 
man,  1. 

Animal  meal,  256. 

Animals,  composition  of  bodies,  93 ; 
mineral  compounds  in,  48;  problems 
in  feeding,  3;  proportions  of  elements 
in,  22;  selection  of,  411;  treatment 
of,  416. 

Ash,  compounds  of,  41 ;  compounds  in 
different  species,  44  ;  distribution 
compounds  of  in  plants,  45;  in  ani- 
mal, 49;  elements  of,  30;  influence  of 


manufacturing  processes  on,  47:    in 
plants,  43;  variations  in  species,  43. 
Assimilation,  definitions  of,  99. 

Beef,  feeding  for  production  of,  339. 

Beet  sugar,  residues  from  manufacture 
of,  240. 

Bile,  115;  function  of,  116. 

Blood,  142;  corpuscles  in,  143;  mineral 
compounds  of,  50. 

Bone,  formation  cf ,  152. 

Bovines,  maintenance  food  for,  297; 
maintenance  rations  for,  299. 

Butter-milk,  254,  255;  as  food  for  swine, 
363. 

Breakfast  foods,  residues  from,  232. 

Breed,  influence  on  digestion,  138;  in- 
fluence on  production,  409,  411. 

Brewer's  grains,  236;  residues,  236. 

Butter,  effect  of  foods  on,  319. 

Calcium,  sources  of,  20;  in  nutrition,  20. 

Calf,  growth  of,  324;  metabolism  of, 
324. 

Calorie,  definition  of,  161. 

Calorimeter,  162;  respiration  form,  201. 

Calves,  composition  of,  403;  feeding  of, 
328:  production  with.  404,  405;  skim- 
milk  for,  329. 

Capillaries,  blood,  119. 

Carbohydrates,  75;  action  of  acids  on, 
86;  action  of  ferments,  86;  animal,  84; 
characteristics  of,  85;  energy  of,  163: 
elements  in,  30;  functions  of ,  155 ;  in- 
fluence of  excess  of,  135;  relative  en- 
ergy values  of,  172;  variations  in  di- 
gestibility, 123. 


(445) 


446 


Index 


Oiirbon,  12;  in  crops,  13;  supply  of,  12, 
13. 

Carbonic  acid,  elimiuatiou  of,  141). 

Casein,  66. 

Cattle  foods,  203;  chemical  differences 
in,  248;  classification  of,  249;  com- 
mercial, 227;  production  of,  258. 

Cellulose,  73;  action  of  ferments  on,  118; 
energy  value  of,  172. 

Chemical  studies,  knowledge  from,  191. 

Chicks,  food  mixtures  for,  390;  rations 
for.  395. 

Chlorine,  in  nutrition,  19;  sources  of, 
19. 

Coarse  foods  vs.  grains,  249. 

Colts,  feeding  of,  333;  foods  for,  337; 
mixtures  for,  338;  oats  as  food  for, 
335. 

Combustion,  measurement  of,  200. 

Compounds,  classes  of,  28;  elements  in 
classes,  30. 

Cooking,  influence  on  digestion,  132. 

Corn  bran,  240. 

Cottonseed,  242;  cake,  243;  hulls,  243; 
meal,  1A2;  oil,  243. 

Cows,  production  with,  404,  405;  selec- 
tion of,  409. 

Crops,  carbon  in,  13;  forage,  204;  legu- 
minous, 262;  productive  capacity,  260; 
soiling,  263;  succession  for  soiling, 
265. 

Crude  fiber,  72;  digestibility  of,  124. 

Curing,  changes  in,  205;  conditions  of, 
206;  vs.  ensiling,  217. 

Dairy  by-products,  254. 

Dextrose,  82. 

Diastase,  function  of,  87. 

Digestibility,  determination  of,  139;  in- 
fluence of  combination  of  nutrients 
on,  135;  conditions  influencing,  126. 

Digestion,  energy  required  for,  165;  of 
food, 98. 

Dried  l)lood,  256. 

Ducks,  food  mixtures  for,  396;  rations 
for,  395. 


Elements,  chemical,  of  nutrition,  11; 
proportions  in  animals,  22;  propor- 
tions in  plants,  21;  sources  of,  12. 

Energy,  available,  163;  carbohydrates 
as  source  of,  155;  expended  by  work 
horses,  369;  fats  as  source  of,  157; 
food  as  source  of,  157;  in  various  food 
compounds,  162;  manifestations  of, 
159;  measurement  of  available,  174; 
net,  164  ;  of  albuminoids,  173  ;  of 
cai'bohydrates,  172;  of  cellulose,  172; 
of  digested  nutrients,  199;  of  fats, 
173;  of  gums,  173;  of  ration,  calcula- 
tion of,  198  ;  protein  as  source  of, 
155;  required  for  chewing,  165;  source 
of,  8;  unit  of,  161;  uses  of,  157. 

Ensilage,  212;  crops  for,  218. 

Ensiling  vs.  field  curing,  217. 

Enzyms,  103. 

Ether  extract,  89;  composition  of,  92; 
digestibility  of,  124. 

Ewes,  feeding  of,  331. 

Exercise,  need  of,  415. 

Extractives,  70;  value  of,  179. 

Fat,  of  milk,  91;  study  of  formation, 
195. 

Fats,  88;  absoi'ption  of,  120;  compara- 
tive energy  values  of,  173  ;  digesti- 
bility of,  124;  elements  in,  30;  energy 
of,  162;  functions  of,  157;  influence 
on  digestion,  137 ;  neutral,  90 ;  of 
body,  source  of,  154,  156;  production 
value  of,  176. 

Fattening,  feeding  for,  341,  351. 

Feces,  121. 

Feeding,  frequency  of,  134. 

Feeding  animals,  problems  in,  3. 

Feeding  standards,  282. 

Feeding  experiments,  utility  of,  188. 

Feeding  stuffs,  classification  of,  251; 
commercial,  227;  commercial  values 
of,  269;  composition  of,  419;  digesti- 
ble substance  in,  276;  digestibility  of, 
427;  energy  of,  163;  fertilizing  cou- 
stituouts  of,  439;  physiological  values 


Index 


447 


of,  272;  popular  valuation,  277;  rela- 
tion to  digestive  processes,  121;  selec- 
tion of,  273;  valuation  by  cow,  279; 
valuation  by  experiments,  278;  valua- 
tions of,  268;  variations,  water  in,  37; 
water  in,  36;  water  in  air  di-y,  37; 
water  in  green,  36. 

Feeds,  ash  in,  47. 

Fermentations,  in  alimentary  canal,  118. 

Ferments,  99;  action  on  carbohydrates, 
80;  coagulating,  63;  of  digestion,  65; 
organized,  100;  unorganized,  100,103. 

Fibrinogen,  61. 

Fish  offals,  256. 

Fodders,  dried,  205;  green,  205. 

Food,  absorption  of,  119;  digestion  of, 
98;  distribution  of,  142;  influences  on 
flavor  of  milk,  321;  relation  to  growth, 
324;  relation  to  milk,  316;  relation  to 
production,  194,  400;  units  of  value, 
401;  use  of,  142,  147. 

Foods,  of  animal  origin,  252. 

Forage  crops,  204;  for  fattening  sheep, 
3.J7;  influence  of  stage  of  growth  on 
composition,  209;  influence  of  stage  of 
growth  on  yield,  208;  harvesting  of, 
207. 

Fowls,  composition  of  bodies  of,  387, 
403;  digestive  apparatus  of,  383;  feed- 
ing of,  379;  production  with,  404,  405. 

Fruit  sugar,  83. 

Gases,  of  digestion,  164. 

Gastric  juice,  112. 

Gelatinoids,  68. 

Germ  oil  meal,  240. 

Globulins,  59;  in  animal,  60;  in  seeds, 

59;  properties  of,  59. 
Glucose    manufacture,   residues  from, 

236. 
Gluten,  energj'  of,  175;  productive  value 

of,  177. 
Gluten  feed,  239. 
Gluten  meal,  239. 
Glycogen,  84;  formation  of,  150. 
Grains  (and  seeds),  225. 


Grape  sugar,  82. 

Grasses,  204. 

Grinding  grains,  influence  ou  digestion, 

133. 
Growing  animals,  feeding  of,  324. 
Growth,  relation  to  food,  325;  sustained 

by  plant,  8. 
Gums,  energy  value  of,  173;  digestibility 

of,  124;  vegetable,  78. 

Hay,  water  in,  37. 

Heart,  the,  144. 

Heat,  body,  regulation  of,  168  ;  effect 
on  albuminoids,  64;  effect  on  cai'bo- 
hydrates,  86. 

Hens,  laying,  rations  for,  393. 

Hogs,  fattening,  growth  of,  358. 

Horses,  influence  of  speed  on  work  of, 
370;  maintenance  food  for,  300;  main- 
tenance rations  for,  302  :  work  per- 
formed by,  368;  working,  feeding  of, 
367;  working,  foods  for,  376;  work- 
ing, food  needs  of,  371  ;  working, 
rations  for,  377  ;  working,  source  of 
rations,  374. 

Hydrochloric  acid,  in  stomach,  112. 

Hydrogen,  15;  in  air,  15;  in  water,  15; 
source  to  animal,  16. 

Intestinal  juice,  function  of,  118. 
Intestines,  the,  114. 
Investigation,  methods  of,  192. 
Iron,  compounds  of,  20;  in  nutrition,  20. 

Keratin,  69. 

Knowledge,  sources  of,  186. 

Lact-albumin,  59. 

Lacteals,  119. 

Lambs,    fattening,    experiments   with, 

353  ;  feeding  of,  331. 
Laws  of  nutrition,  182. 
Legumes,  204. 
Le%Tilose,  83. 
Lime,  in  animal,  48  ;   for  poultry,  390  ; 

in  plants,  45. 


448 


Index 


Linseed  meal,  245  ;    new  process,  246  ; 

old  process,  246. 
Liuseeil  oil.  245. 
Liver,  the,  150. 
Lungs,  the,  146. 

Maintenance  food  for  bovines,  297;  for 

horses,  300. 
Maintenance  rations,  295;  for  bovines, 

299;  for  horses,  302;  for  poultry,  ?93; 

sources  of,  296;  uses  of,  295. 
Maize,  influence  stage  of  growth,  211; 

productivity  of,  261. 
Maize  kernel,  237. 
Malt  sprouts,  236. 
Maltose,  82. 

Man,  relation  to  animal,  1. 
Mares,  feeding  of,  334. 
Matter,   classes    of,    26  ;    combustible, 

26;  incombustible,  26;  inorganic,  28; 

organic,  28. 
Meat,  albumin  in,  58  ;    production   of, 

339. 
Meat  meal,  256. 
Metabolic  wastes,  errors  caused  by,  136, 

140. 
Milk,  composition  of,  305;  as  cattle  food, 

252;    demands  for  secretion  of,  309; 

effect  of  food  on,  316,  321;  foi*mation 

solids,  308;    of   various   species,  253; 

production  of,  304;  protein  needs  for 

production  of,  310;  ration  for  produc- 
ing, 309,  312;  secretion  of,  306;  source 

of  solids,  307;  sources  protein  in  ration 

for,  313. 
Milk  sugar,  85. 
Mineral  compounds,  elimination  of,  149 ; 

function  of,  152. 
Molasses,   energy  of,  175 ;    production 

value  of,  177. 
Mouth,  the,  104. 
Mutton,  production  of,  349. 
Muscular  power,  source  in  plants,  9. 
Muscular  tissue,  153. 
Mastication,    energy    requirements, 

165. 


Nitrogen,  16;  compounds,  16,  51;  in  air, 
16;  in  soil,  16. 

Nitrogen-free  compounds,  71. 

Nitrogen-free  extract,  74;  energy  values 
of  compounds,  171. 

Nuclein,  67;  special  value  of,  180. 

Nutrients,  combustion  of,  147;  energy 
relations  of,  166;  functions  of,  151; 
physiological  values  of,  170;  produc- 
tion values  of,  175;  relative  energy 
values  of,  171;  storage  of,  147. 

Nutrition,  chemical  elements  of,  11; 
compounds  of,  25;  laws  of ,  182. 

Nutritive  ratio,  283. 

Oat  feeds,  233;  grain,  233;    hulls,  233; 

kernel,  233. 
Oats,  as  food  for  colts,  335. 
Oils,  energy  of,  175;    productive  value 

of,  177. 
Oil  meals,  241. 
Oils,  the,  88. 
Ova-albumen,  59. 
Oxygen,  14;  in  air,  14;  in  earth,  14;  in 

hmgs,  146;  in  water,  14;  relation  lo 

animal  life,  14;  relation  to  energy,  15; 

use  of,  147. 
Oxen,    fattening,     experiments     with, 

343. 

Palatableness,  importance  of,  280;  in- 
fluence on  digestion,  126. 

Pancreatic  juice,  117;  function  of,  117. 

Pectin  bodies,  80. 

Pentosans,  energy  value  of,  173. 

Pepsin,  113. 

Peptones,  absorption  of,  120. 

Phosphoric  acid,  in  animal,  48;  varia- 
tions in  i>lants,  45. 

Phosphorus,  in  nutrition,  19;  sources' 
of,  18. 

Physiological  studies,  knowledge  from, 
191. 

Pig,  fat,  composition  of,  359;  feeding 
of,  361;  foods  for,  363,  365;  relation 
of  food  to  growth,  302.  . 


Index 


449 


n, lilts,  relation  to  animal  life,  7,  8,  9; 
albumin  in,  59;  distribution  ash  com- 
pounds in,  45;  liN^ng,  water  in,  33; 
mineral  compounds  of,  43 ;  propor- 
tions of  elements  in,  21. 

Potash,  variations  in  plants,  45. 

Pork,  production  of,  357. 

Potassium,  where  found,  IJ;  in  nutri- 
tion, 19. 

PoultiT,  effects  of  food  with,  382;  feed- 
ing of,  379;  foods  for,  379;  food  needs 
of,  389;  food  mixtures  for,  39G;  main- 
tenance rations  for,  393;  rations  for 
chicks,  394;  rations  for  laying  hens. 

Practice,  conclusions  of,  187. 

Preservation  of  fodders,  influence  on 
digestion,  129. 

Preparation  of  foods,  influence  on  diges- 
tion, 129. 

Production,  relation  of  food  to,  194,  400; 
unit  of,  401. 

Proteids,  55;  composition,  56  ;  com- 
pound, 06;  examples  of,  57. 

Protein,  classification  compounds  of, 
54:  combustion  of,  147;  definition  of, 
52;  elements  in,  30;  functions  of,  153; 
how  estimated,  53;  in  fattening  ra- 
tion, 341,  3.52;  in  work  horse  ration, 
375;  influence  on  digestion,  137;  need 
of  in  milk  ration,  310  ;  production 
value  of,  175;  proportion  in  ration, 
291;  relation  to  muscular  effort,  167; 
relative  importance  of  compound,  178; 
supplj'  of,  262;  sources  of  for  milk 
ration,  313;  variations  in  digestibility 
of,  122. 

Ptyalin,  107. 

Ration,  influence  of  quantity  on  digest- 
ibility, 127. 

Rations,  adaptation  of,  281;  calculation 
of,  285;  compounding  of,  280;  fat- 
tening, selection  of,  347;  for  fatten- 
ing steers,  342,  348;  for  laying  hens, 
393;   for  milk  production,   309.  312; 

CC 


for  poiiltrs',  392;  for  work  horses, 
374,  377;  for  young  birds,  394;  main- 
tenance, 295;  maintenance  for  bo- 
\ines,  299;  maintenance  for  horses, 
302;  maintenance  for  poultry,  393; 
manipulation  of,  413;  palatableness 
of,  280  ;  proportion  of  protein,  291  ; 
quantity  of,  414;  relation  to  qualiiv 
of  product,  292;  relation  to  prices  and 
supply,  293 ;  relation  to  weight  of 
animal.  289;  selection  of,  280;  stand- 
ards for,  282,  342,  345. 

Rennin,  113. 

Respiration  apparatus,  196. 

Rigor  mortis,  cause  of,  61. 

Roots  (and  tubers),  224. 

Roots,  productivity  of,  201;  storage  of. 


Saccharose,  81. 

Saliva,  106;  function  of,  107. 

Salt,  in  feeding  poultry,  391;  influence 
on  digestion,  l.']3. 

Salts,  absorption  of,  120. 

Sand,  in  feeding  poulti-y,  391. 

Serum  albumin,  59. 

Sheep,  composition  of,  403;  fattening, 
experiments  with,  353;  fattening,  food 
needs  of,  351;  fattening,  food  stand- 
ards, 352;  fattening,  growth  of,  350; 
production  with,  404,  405  ;  selection 
of  ration  for,  355. 

Silage,  212;  changes  in,  213 ;  cutting 
material  for,  221;  formation  of,  213; 
maturity  crop  for,  220. 

Silo,  construction  of,  219;  changes  in, 
213;  extent  of  loss  from,  215;  filling 
of,  220;  nature  of  loss  from,  214;  rate 
of  filling,  221. 

Skim-milk,  254,  255;  as  food  for  swine, 
363. 

Sl.iughter-house  refuses,  256. 

Sodium,  in  nutrition,  20;  sources  of,  19. 

Soil,  nitrogen  in,  16. 

Soiling,  263;  crops  for,  265;  succession 
of  crops,  266;  systems  of,  205. 


450 


Index 


Soiling  crops,  for  swine,  36G. 

Sows,  feeding  of,  SCO. 

Species,  influence  on  digestion,  137. 

Stage  of  growth,  influence  on  digestion, 
130  ;  influence  on  forage  crops,  208. 

Standards,  German,  282. 

Starch,  energy  of ,  175;  distribution  in 
seeds,  77  ;  productive  value  of,  176, 
177;  properties  of,  76;  residues  from 
manufacture  of.  236. 

Starch  (sugar  corn)  feed,  239. 

Starch  grains,  forms  of,  76. 

Starches,  the,  75. 

Steers,  composition  of,  403  ;  composi- 
tion of  increase  of,  310  ;  fattening, 
experiments  with,  343,  345;  fattening, 
food  needs  of,  341;  fattening,  food  for, 
344;  production  with,  404,  405. 

Stomach,  108;  of  horse,  113;  of  pig,  113; 
of  ruminants,  108. 

Storage,  influence  on  digestiliility,  135. 

Straw,  energy  of,  175;  production  value 
of,  177. 

Straws,  the,  223. 

Sugar,  absorption  of,  120. 

Sugar  beet  molasses,  241. 

Sugar  beet  pulp,  240. 

Sugars,  the,  80. 

Sullia-,  in  nutrition,  18;  sources  of,  18. 


Swine,  composition  of,  403:  production, 

404,  405. 

Teeth,  the,  105. 
Temperature  of  stable,  415. 
Trypsin,  117. 

Urea,  elimination  of,  149. 

Valuation  feeding  stiiffs,  268;  basis  of, 
274  ;  commercially,  269  ;  physiologi- 
cally, 272;  popular  standards,  277. 

Vitellin,  62. 

Water,  30;  amount  required  by  plants, 
36;  elimination  of,  149;  hydrogen  in, 
15;  in  animal,  38  ;  in  fattening  in- 
crease, 40;  in  feeding  poultry,  389;  in 
feeding  stuffs,  36;  in  hay,  37;  in  liv- 
ing plants,  33;  oxygen  in,  14;  varia- 
tions in  feeding  stuffs,  37;  in  plants, 
33. 

Watering,  freqiieney  of,  134. 

Wastes,  elimination  of,  148. 

Wheat,  offals  from,  228. 

Wheat  kernel,  228;  proportion  of  parts, 
230. 

Wheat  offals,  composition  of,  231. 

Whey,  254,  255. 


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WORKS     BY    PROFESSOR     BAILEY 

T^HE  EVOLUTION  OF  OUR  NA- 
TIVE FRUITS.  By  L.  H.  BAILEY,  Pro- 
fessor of   Horticulture  in  the  Cornell  University. 

472    PACES— 126    ILLUSTRATIONS  — S2. 00 

In  this  entertaining  volume,  the  origin  and  de- 
velopment of  the  fruits  peculiar  to  North  America 
are  inquired  into,  and  the  personality  of  those  horti- 
cultural pioneers  whose  almost  forgotten  labors 
have  given  us  our  most  valuable  fruits  is  touched 
upon.  There  has  been  careful  research  into  the 
history  of  the  various  fruits,  including  inspection 
of  the  records  of  the  great  European  botanists  who 
have  given  attention  to  American  economic  botany. 
The  conclusions  reached,  the  information  presented, 
and  the  suggestions  as  to  future  developments,  can- 
not but  be  valuable  to  any  thoughtful  fruit-grower, 
while  the  terse  style  of  the  author  is  at  its  best  in 
his  treatment  of  the  subject. 

The  Evolution  of  our  Native  Fruits  discusses  The  Rise  of 
the  American  Grape  (North  America  a  Natural  Vineland,  Attempts 
to  Cultivate  the  European  Grape,  The  Experiments  of  the  Dufours, 
The  Branch  of  Promise,  John  Adlura  and  the  Catawba,  Rise  of 
Commercial  Viticulture,  Why  Did  the  Early  Vine  Experiments  Fail  ? 
Synopsis  of  the  American  Grapes) ;  The  Stranj^e  History  of  the  Mul- 
berries (The  Early  Silk  Industry,  The  "Multicaulis  Craze,");  Evohi- 
tion  of  American  Plums  and  Cherries  (Native  Plums  in  General, 
The  Chickasaw,  Hortulana,  Marianna  and  Beach  Plum  Groups, 
Pacific  Coast  Plum,  Various  Other  Types  of  Plums,  Native  Cherries, 
Dwarf  Cherry  Group) ;  Native  Apples  (Indigenous  Species,  Amelio- 
ration has  begun);  Origin  of  American  Raspberry-growing  (Early 
American  History,  Present  Types,  Outlying  Types);  Evolution  of 
Blackberry  and  Dewberry  Culture  (The  High-bush  Blackberry  and 
Its  Kin,  The  Dewberries,  Botanical  Names);  Various  Types  of 
Berry-like  Fruits  (The  Gooseberry,  Native  Currants,  Juneberry, 
Buffalo  Berry,  Elderberry,  High-biish  Cranberry,  Cranberry,  Straw- 
berry); Various  Types  of  Tree  Fruits  (Persimmon,  Custard-Apple 
Tribe,  Thorn-Apples,  Nut-Fruits) ;  General  Remarks  on  the  Improve- 
ment of  our  Native  Fruits  (What  Has  Been  Done,  What  Probably 
Should  Be  Done). 


T 


WORKS    BY   PROFESSOR    BAILEY 

HE  SURVIVAL  OF  THE  UNLIKE: 

A  Collection  of  Evolution  Essays  Suggested 
by  the  Study  of  Domestic  Plants.     By  L.  H. 

BAILEY,    Professor  of    Horticulture    in    the  Cornell 
University. 

THIRD     EDITION- 515    PACES  —  22    ILLUSTRATIONS  — $2.00 

To  those  interested  in  the  underlying  philoso]3hy 
of  plant  life,  this  volume,  written  in  a  most  enter- 
taining style,  and  fully  illustrated,  will  prove  wel- 
come. It  treats  of  the  modification  of  plants  under 
cultivation  upon  the  evolution  theory,  and  its  atti- 
tude on  this  interesting  subject  is  characterized 
by  the  author's  well-known  originality  and  inde- 
pendence of  thought.  Incidentally,  there  is  stated 
much  that  will  be  valuable  and  suggestive  to  the 
working  horticulturist,  as  well  as  to  the  man  or 
woman  impelled  by  a  love  of  nature  to  horticul- 
tural pursuits.  It  may  well  be  called,  indeed,  a 
philosophy  of  horticulture,  in  which  all  interested 
may    find  inspiration  and  instruction. 

The  Survival  of  the  Unlike  comprises  thirty  essays  touching 
upon  The  General  Fact  and  Philosophy  of  Evolution  (The  Plant 
Individual,  Expei-imental  Evolution,  Coxey's  Army  and  the  Russian 
Thistle,  Recent  Progress,  etc.);  Expounding  the  Fact  and  Causes  of 
Variation  (The  Supposed  Correlations  of  Quality  in  Fruits,  Natural 
History  of  Sjmonj-ras,  Reflective  Impressions,  Relation  of  Seed- 
bearing  to  Cultivation,  Variation  after  Birth,  Relation  between 
American  and  Eastern  Asian  Fruits,  Horticultural  Geography,  Prob- 
lems of  Climate  and  Plants,  American  Fruits,  Acclimatization,  Sex 
in  Fruits,  Novelties,  Promising  Varieties,  etc.);  ard  Tracing  the 
Evolution  of  Particular  Types  of  Plants  (the  Cultivated  Strawberry, 
Battle  of  the  Plums,  Grapes,  Progress  of  the  Carnation.  Petunia. 
The  Garden  Tomato,  etc.). 


CYCLOPEDIA  Of 
AMERICAN  HORTICULTURE 

COMPRISING  DIRECTIONS  FOR  THE  CULTIVATION  OF  HORTICULTURAL 
CROPS,  AND  ORIGINAL  DESCRIPTIONS  OF  ALL  THE  SPECIES  OF 
FRUITS,  VEGETABLES,  FLOWERS  AND  ORNAMENTAL  PLANTS  KNOWN 
TO    BE    IN     THE    MARKET    IN     THE     UNITED    STATES     AND     CANADA 

By  L.   H.   bailey 

ASSISTED    BY  MANY   EXPERT  CULTIVATORS  AND    BOTANISTS 

In  Four  Quarto  Volumes, 
Illustrated  with  over  Two  Thousand  Original  Engravings 

THIS  monumental  work,  the  most  comprehensive 
review  of  the  vegetable  world  j^et  made  by  an 
American,  is  now  in  the  press.  Though  distinctly 
an  American  work,  not  only  plants  indigenous  to 
the  North  American  continent  are  mentioned,  but 
also  all  the  species  known  to  be  in  the  horticul- 
tural trade  in  North  America,  of  whatever  origin. 
It  is  really  a  survey  of  the  cultivated  plants  of  the 
world. 

The  Editor,  Professor  L.  H,  Bailey,  has  been 
gathering  material  for  this  Cyclopedia  for  many 
years.  He  has  enlisted  the  cooperation  of  many 
men  of  attainments,  either  in  science  or  practice, 
and  the  Cyclopedia  has  the  unique  distinction  of 
pi-esenting  for  the  first  time,  in  a  carefully  arranged 
and  perfectly  accessible  form,  the  best  knowledge  of 
the  best  specialists  in  America  upon  gardening, 
fruit-growing,   vegetable   culture,   forestry,   and   the 


like,  as  well  as  exact  botanical  information.  It  is 
all  fresh,  and  not  a  rehash  of  old  material.  No 
precedent  has  been  followed  ;  the  work  is  uj^on  its 
own  original  plan. 

Many  scientific  botanical  authors  of  justly  high 
repute  decline  to  give  attention  to  the  important 
characters  of  cultivated  plants,  confining  their  work 
to  the  species  in  the  original  forms  only.  Pro- 
fessor Bailey  takes  the  view  that  a  subject  of  com- 
mercial importance,  one  which  engages  the  attention 
and  affects  the  livelihood  of  thousands  of  bright 
people,  is  de<.'idedly  worthy  the  investigation  of  the 
trained  botanist.  In  the  Cyclopedia  of  American 
Horticulture,  therefore,  very  full  accounts  are  given 
of  the  botanical  features  of  all  important  commercial 
plants,  as  the  apple,  cabbage,  rose,  etc.  At  the  same 
time,  practical  cultivators  submit  observations  upon 
culture,  marketing,  and  the  like,  and  frequently  two 
opinions  are  presented  upon  the  same  subject  from 
different  localities,  so  that  the  reader  may  have 
before  him  not  only  complete  botanical  information, 
but  very  full}-  the  best  practice  in  the  most  favor- 
able localities  for  the  perfection  of  any  fruit  or 
vegetable  or  economic  plant. 

ILLUSTRATIONS 

The  pictorial  character  of  the  work  is  likewise  nota- 
ble. There  are  nearly  three  thousand  illustrations, 
and  they  are  made  expressly  for  this  work,  either 
from  accurate  photographs  or  from  the  specimens. 
These  illustrations  have  been    drawn   by   competent 


horticultural  artists,  in  nearly  every  case  under  thy 
eye  of  the  Editor,  or  with  the  supervision  of  some 
one  of  the  sub-editors.     No  "trade"  cuts  are  used. 

[n  planning  the  illustrations,  artistic  effect  has 
been  kept  in  view,  and  w^hile  no  drawing  is  used 
which  does  not  show  its  subject  with  perfect  scien- 
tific accuracy,  the  monotonous  so-called  "botanical" 
outlines,  often  made  from  lifeless  herbarium  speci- 
mens, are  notably  absent.  The  intention  is  to  show 
the  life  of  the  plant,  not  merely  its  skeleton. 

CONTRIBUTORS,  SYSTEM,  ETC. 

As  above  mentioned,  the  contributors  are  men 
eminent  as  cultivators  or  as  specialists  in  the  various 
subjects.  The  important  articles  are  signed,  and  it 
is  expected  that  the  complete  work  will  include  fully 
5,000  signed  contributions  by  horticulturists,  culti- 
vators and  botanists. 

The  arrangement  is  alphabetical  as  to  the  genera, 
but  systematic  in  the  species.  A  very  simple  but 
complete  plan  of  key -letters  is  used,  and  the  whole 
arrangement  is  toward  ease  of  reference  as  well  as 
completeness  of  information.  To  each  large  genus 
there  is  a  separate  alphabetic  index. 

Important  commercial  subjects  are  treated  usually 
under  the  best  known  name,  whether  it  be  the 
scientific  or  "common"  designation.  Thus,  the  apple 
is  fully  discussed  as  apple,  rather  than  as  Pyrus 
Mains,  and  the  carnation  comes  into  view  in  the 
third  letter  of  the  alphabet,  not  as  Dianthus  Caryo- 
phyllus.     Carefully  edited   cross-references   make   it 


easy  to  find  any  desired  subject,  however,  in  the 
shortest  time. 

The  plan  of  presenting  the  full  details  of  cul- 
ture of  important  plants,  through  the  views  of 
acknowledged  practical  experts  upon  the  various 
subjects,  assures  the  great  value  of  the  book  to  the 
man  or  woman  who  is  obtaining  a  living  from 
horticultural  pursuits. 

A  special  feature  of  the  Cyclopedia  of  American 
Horticulture  is  its  wealth  of  bibliographic  reference. 
The  world's  horticultural  literature  has  been  thor- 
oughly searched,  and  most  carefully  indexed,  so  that 
the  student  will  find  citations  to  nearly  every  avail- 
able article  or  illustration  upon  any  subject  consulted. 

DETAILS  Of  PUBLICATION 

The  Cyclopedia  of  American  Horticulture  is  to 
be  completed  in  four  handsome  quarto  volumes, 
embracing  about  two  thousand  pages,  with  more 
than  that  number  of  original  illustrations.  It  is 
carefully  printed  upon  specially  made  paper  of  a 
permanent  character.  Vol.  I  (A  to  D,  509  pages, 
743  illustrations,  9  plates),  Vol.  H  (E  to  M,  544 
pages,  710  illustrations,  10  plates),  and  Vol.  HI  (N 
to  Q,  432  pages,  606  illustrations,  11  plates)  are  now 
ready,  and  the  work  will  be  completed  early  in  1901. 

The  work  is  sold  only  by  subscription,  and 
orders  will  be  accepted  for  the  full  set  only. 
Terms  and  further  information  may  be  had  of 
the   Publishers, 

THE    MACMILLAN    COMPANY 

No.  66   Fifth  Avenue  NEW    YORK 


WORKS    BY    PROFESSOR    BAILEY 

ESSONS  WITH  PLANTS:  Surges- 
tions  for  Seeing  and  Interpreting  Some  of 
the  Common  Forms  of  Vegetation.  By  L. 
H.  BAILEY,  Professor  of  Horticulture  in  the  Cornell 
University,  with  delineations  from  nature  by  W.  S. 
HOLDSWORTH,  of  the  Agricultural  College  of 
Michigan. 

SECOND  EDITION— 491    PACES-446  ILLUSTRATIONS— I  2  MO- 
CLOTH— SI.  10  NET 

There  are  two  ways  of  looking  at  nature.  The 
old  tvay,  which  you  have  found  so  unsatisfactory, 
was  to  classify  everything — to  consider  leaves,  roots, 
and  whole  plants  as  formal  herbarium  specimens, 
forgetting  that  each  had  its  own  story  of  growth 
and  development,  struggle  and  success,  to  tell. 
Nothing  stifles  a  natural  love  for  i)lants  more  effect- 
ually than  that  old  way. 

The  new  way  is  to  watch  the  life  of  every  grow- 
ing thing,  to  look  upon  each  plant  as  a  living 
ereatu-re,  whose  life  is  a  story  as  fascinating  as  the 
story  of  any  favorite  hero.  "Lessons  with  Plants" 
is  a  book  of  stories,  or  rather,  a  book  of  plaj^s,  for 
we  can  see  each  chapter  acted  out  if  we  take  the 
trouble  to  loolc  at  the  actors. 

"I  have  spent  some  time  inmost  delightful  examination  of  it,  and  the 
longer  I  look,  the  better  I  like  it.  I  find  it  not  only  full  of  interest,  but 
eminently  suggestive.  I  know  of  no  book  which  begins  to  do  so  mucli  to 
open  the  eyes  of  the  student— whether  pupil  or  teacher  — to  the  wealth  of 
meaning  contained  in  simple  plant  forms.  Above  all  else,  it  seems  to  bo 
hi[\  of  suggestions  that  help  one  to  learn  the  language  of  plants,  so  tbey 
may  talk  to  him."— Uaewin  L.  Bardwell,  Suiter  hit  endent  of  Schools,  Biiifi- 
hamton. 

"It  is  an  admirable  book,  and  cannot  fail  both  to  awaken  interest  in 
the  subject,  and  to  serve  as  a  helpful  and  reliable  gnide  to  yoiing  students 
of  phmt  life.  It  will,  I  think,  fill  an  important  place  in  secondary  schools, 
and  comes  at  an  opportune  time,  when  helps  of  this  kind  are  needed  and 
eagerly  sought."— Professor  V.  M.  Si'AiiDiNU,  University  of  Michigan. 

FIRST    LESSONS    WITH    PLANTS 

An  Abridf:reinent  of  the  above.  117  pages — 116  illustra- 
tions— 40  cents  net. 

'^ 
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Webster  Family  Library  of  Veterinary  JViedicine 
Cummings  Scliool  of  Veterinary  Medicine  at 
Tufts  University    • 
200  Westboro  Road 
North  Grafton,  iVIA  01 53R 


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